in motion at a time, the shafting and the belts for the total number is
constantly whirling, absorbing uselessly a lot of power. If, however,
a separate motor be fitted to each lathe, the workman can switch it on
and off at his pleasure.

The New York Shipbuilding Company, a very modern enterprise, depends
mainly on electrical power for driving its machinery, in preference to
belting, compressed air, or water. Let us stroll through the various
shops, and note the uses to which the current has been harnessed.
Before entering, our attention is arrested by a huge gantry crane,
borne by two columns which travel on rails. From the cross girder,
or bridge, 88 feet long, hang two lifting magnets, worked by 25 h.p.
motors, which raise the load at the rate of 20 feet per minute. Motors
of equal power move the whole gantry along its rails over the great
piles of steel plates and girders from which it selects victims to feed
the maw of the shops.

The main building is of enormous size, covering with its single roof no
less than eighteen acres! Just imagine four acres of skylights and two
acres of windows, and you may be able to calculate the little glazier's
bill that might result from a bad hailstorm. In this immense chamber
are included the machine, boiler, blacksmith, plate, frame, pipe, and
mould shops, the general storerooms, the building ways, and outfitting
slips. "The material which enters the plate and storage rooms at one
end, does not leave the building until it goes out as a part of the
completed ship for which it was intended, when the vessel is ready to
enter service; there are installed in one main building, and under one
roof, all the material and machinery necessary for the construction of
the largest ship known to commerce, and eight sets of ship-ways, built
upon masonry foundations, covered by roofs of steel and glass, and
spanned by cranes up to 100 tons lifting capacity, are practically as
much a part of the immense main building as the boiler shop or machine
shop."[10]

A huge 100-ton crane of 121-foot span dominates the machine-shop and
ship-ways at a height of 120 feet. It toys with a big engine or boiler,
picking it up when the riveters, caulkers, and fitters have done their
work, and dropping it gently into the bowels of a partly-finished
vessel. A number of smaller cranes run about with their loads. Those
which handle plates are, like the big gantry already referred to,
equipped with powerful electro-magnets which fix like leeches on the
metal, and will not let go their hold until the current is broken by
the pressing of a button somewhere on the bridge. Sometimes several
plates are picked up at once, and then it is pretty to see how the man
in charge drops them in succession, one here, another there, by merely
opening and closing the switch very quickly, so that the plate furthest
from the magnets falls before the magnetism has passed out of the
nearer plates.

Another interesting type is the extension-arm crane, which shoots out
an arm between two pillars, grips something, and pulls it back into the
main aisle, down which it travels without impediment.

On every side are fresh wonders. Here is an immense rolling machine,
fed with plates 27 feet wide, which bends the 1-1/8-inch thick metal
as if it were so much pastry; or turns over the edges neatly at the
command of a 50 h.p. motor. There we have an electric plate-planer
scraping the surface of a sheet half the length of a cricket pitch. As
soon as a stroke is finished the bed reverses automatically, while the
tool turns over to offer its edge to the metal approaching from the
other side. All so quietly, yet irresistibly done!

Now mark these punches as they bite 1-1/4-inch holes through steel
plates over an inch thick, one every two seconds. A man cutting wads
out of cardboard could hardly perform his work so quickly and well.
Almost as horribly resistless is the circular saw which eats its way
quite unconcernedly through bars six inches square, or snips lengths
off steel beams.

What is that strange-looking machine over there? It has three columns
which move on circular rails round a table in the centre. Up and down
each column passes a stage carrying with it a workman and an electric
drill working four spindles. Look! here comes a crane with a boiler
shell, the plates of which have been bolted in position. The crane lets
down its load, end-up, on to the table, and trots off, while the three
workmen move their columns round till the twelve drills are opposite
their work. Then whirr! a dozen twisted steel points, ranged in three
sets of four, one drill above the other, bite into the boiler plates,
opening out holes at mathematically correct intervals all down the
overlapping seam-plates. This job done, the columns move round the
boiler, and their drills pierce it first near the lower edge, then near
the upper. The crane returns, grips the cylinder, and bears it off to
the riveters, who are waiting with their hydraulic presses to squeeze
the rivets into the holes just made, and shape their heads into neat
hemispheres. As it swings through the air the size of the boiler is
dwarfed by its surroundings; but if you had put a rule to it on the
table you would have found that it measured 20 feet in diameter and as
many in length. A few months hence furnaces will rage in its stomach,
and cause it to force tons of steam into the mighty cylinders driving
some majestic vessel across the Atlantic.

We pass giant lathes busy on the propeller shafts, huge boring mills
which slowly smooth the interior of a cylinder, planers which face the
valve slides; and we arrive, eye-weary, at the launching-ways where
an ocean liner is being given her finishing touches. Then we begin
to moralise. That 600-foot floating palace is a concretion of parts,
shaped, punched, cut, planed, bored, fixed by electricity. Where does
man come in? Well, he harnessed the current, he guided it, he said "Do
this," and it did it. Does not that seem to be his fair share of the
work?

FOOTNOTES:

[5] _Industrial Biographies_, Dr. S. Smiles.

[6] _Industrial Biographies._

[7] _Industrial Biographies._

[8] _Chambers's Encyclopædia._

[9] Mr. A. F. Petch in _Cassier's Magazine_.

[10] _Cassier's Magazine._

CHAPTER IV

PORTABLE TOOLS

"If the mountain won't come to Mahomet," says the proverb, "Mahomet
must go to the mountain."

This is as true in the workshop as outside;--Mahomet being the tool,
the mountain the work on which it must be used. With the increase in
size of machinery and engineering material, methods half a century old
do not, in many cases, suffice; especially at a time when commercial
competition has greatly reduced the margin of profits formerly expected
by the manufacturer.

To take the case of a large shaft, which must have a slot cut along it
on one side to accommodate the key-wedge, which holds an eccentric for
moving the steam valves of a cylinder, or a screw-propeller, so that it
cannot slip. The mass weighs, perhaps, twenty tons. One way of doing
the job is to transport the shaft under a drill that will cut a hole at
each end of the slot area, and then to turn it over to the planer for
the intermediate metal to be scraped out. This is a very toilsome and
expensive business, entailing the use of costly machinery which might
be doing more useful work, and the sacrifice of much valuable time.
Inventors have therefore produced portable tools which can perform work
on big bodies just as efficiently as if it had been done by larger
machinery, in a fraction of the time and at a greatly reduced cost. To
quote an example, the cutting of a key-way of the kind just described
by big machines would consume perhaps a whole day, whereas the light,
portable, easily attached miller, now generally used, bites it out in
ninety minutes.

PNEUMATIC TOOLS

The best known of these is the pneumatic hammer. It consists of a
cylinder, inside which moves a solid piston having a stroke of from
half an inch to six inches. Air is supplied through flexible tubing
from a compressing pump worked by steam. The piston beats on a loose
block of metal carried in the end of the tool, which does the actual
striking. The piston suddenly decreases in diameter at about the centre
of its length, leaving a shoulder on which air can work to effect the
withdrawal stroke. By a very simple arrangement of air-ports the piston
is made to act as its own valve. As the plane side of the piston has
a greater area than that into which the piston-rod fits, the striking
movement is much more violent than the return. Under a pressure of
several hundreds of pounds to the square inch a pneumatic hammer
delivers upwards of 7,000 blows per minute; the quick succession of
comparatively gentle taps having the effect of a much smaller number of
heavier blows. For the flat hammer head can be substituted a curved die
for riveting, or a chipping chisel, or a caulking iron, to close the
seams of boilers.

The riveter is peculiarly useful for ship and bridge-building work
where it is impossible to apply an hydraulic tool. A skilled workman
will close the rivet heads as fast as his assistant can place them
in their holes; certainly in less than half the time needed for
swing-hammer closing.

Even more effective proportionately is the pneumatic chipper. The
writer has seen one cut a strip off the edge of a half-inch steel plate
at the rate of several inches a minute. To the uninitiated beholder it
would seem impossible that a tool weighing less than two stone could
thus force its way through solid metal. The speed of the piston is so
high that, though it scales but a few pounds, its momentum is great
enough to advance the chisel a fraction of an inch, and the individual
advances, following one another with inconceivable rapidity, soon total
up into a big cut.

Automatic chisels are very popular with ornamental masons, as they lend
themselves to the sculpturing of elaborate designs in stone and marble.

Their principle, modified to suit work of another character, is seen in
percussive rock drills, such as the Ingersoll Sergeant. In this case
the piston and tool are solid, and the air is let into the cylinder
by means of slide valves operated by tappets which the piston strikes
during its movements. Some types of the rock-drill are controllable
as to the length of their stroke, so that it can be shortened while
the "entry" of the hole is being made and gradually increased as the
hole deepens. For perpendicular boring the drill is mounted on a
heavily weighted tripod, the inertia of which effectively damps all
recoil from the shock of striking; for horizontal work, and sometimes
for vertical, the support is a pillar wedged between the walls of the
tunnel, or shaft. An ingenious detail is the rifled bar which causes
the drill to rotate slightly on its axis between every two strokes,
so that it may not jam. The drills are light enough to be easily
erected and dismantled, and compact, so that they can be used in
restricted and out-of-the way places, while their simplicity entails
little special training on the part of the workman. With pneumatic and
other power-drills the cost of piercing holes for explosive charges is
reduced to less than one-quarter of that of "jumping" with a crowbar
and sledgehammers. With the hand method two men are required, usually
more; one man to hold, guide, and turn the drill; and the other, or
others, to strike the blows with hammers. The machine, striking a
blow far more rapidly than can be done by hand, reduces the number
of operators to one man, and perhaps his helper. So durable is the
metal of these wonderful little mechanisms that the delivery of
360,000 blows daily for months, even though each is given with a force
of perhaps half a ton, fails to wear them out; or at the most only
necessitates the renewal of some minor and cheap part. The debt that
civilisation owes to the substitution of mechanical for hand labour
will be fully understood by anyone who is conversant with the history
of tunnel-driving and mining.

Another application of pneumatics is seen in the device for cutting
off the ends of stay bolts of locomotive boilers. It consists of a
cylinder about fifteen inches in diameter, the piston of which operates
a pair of large nippers capable of shearing half-inch bars. The whole
apparatus weighs but three-quarters of a hundredweight, yet its power
is such that it can trim bolts forty times as fast as a man working
with hammer and cold-chisel, and more thoroughly.

Then there is the machine for breaking the short bolts which hold
together the outer and inner shells of the water-jacket round a
locomotive furnace. A threaded bar, along which travels a nut, has a
hook on its end to catch the bolt. The nut is screwed up to make the
proper adjustment, and a pneumatic cylinder pulls on the hook with a
force of many tons, easily shearing through the bolt.

We must not forget the _pneumatic borer_ for cutting holes in wood
or metal, or enlarging holes already existing. The head of the borer
contains three little cylinders, set at an angle of 120°, to rotate
the drill, the valves opening automatically to admit air at very high
pressures behind the pistons. Any carpenter can imagine the advantage
of a drill which has merely to be forced against its work, the movement
of a small lever by the thumb doing the rest!

Next on the list comes the _pneumatic painter_, which acts on much the
same principle as the scent-spray. Mechanical painting first came to
the fore in 1893, when the huge Chicago Exposition provided many acres
of surfaces which had to be protected from the weather or hidden from
sight. The following description of one of the machines used to replace
hand-work is given in _Cassier's Magazine_: "The paint is atomized and
sprayed on to the work by a stream of compressed air. From a small
air-compressor the air is led, through flexible hose, to a paint-tank,
which is provided with an air-tight cover and clamping screws. The
paint is contained in a pot which can be readily removed and replaced
by another when a different colour is required. This arrangement of
interchangeable tins is also important as facilitating easy cleaning.
The container is furnished with a semi-rotary stirrer, the spindle
passing through a stuffing-box in the cover, and ending in a handle by
which the whole thing complete may be carried about. The compressor is
necessarily fixed or stationary, but the paint-tank, connected to it by
the single air-hose, can be moved close to the work, while the length
of hose from the tank to the nozzle gives the freedom of movement
necessary. Air-pressure is admitted to the tank by a bottom valve, and
forces the paint up an internal pipe and along a hose from the tank
to the spraying nozzle, to which air-pressure is also led by a second
hose. The nozzle is practically an injector of special form. The flow
of paint at the nozzle is controlled by a small plug valve and spring
lever, on which the operator keeps his thumb while working, and which,
on release, closes automatically. When it is required to change from
one colour to another, or to use a different material, such as varnish,
the can, previously in use, is removed, and air, or, if necessary,
paraffin oil, is blown through the length of hose which supplies the
paint until it is completely clean." The writer then mentions as an
instance of the machine's efficiency that it has covered a 30 feet by 8
feet boiler in less than an hour, and that at one large bridge yard a
70 feet by 6 feet girder with all its projecting parts was coated with
boiled oil in two hours--a job which would have occupied a man with
a brush a whole day to execute. Apart from saving time, the machine
produces a surface quite free from brush marks, and easily reaches
surfaces in intricate mouldings which are difficult to get at with a
brush.

The _pneumatic sand-jet_ is used for a variety of purposes: for
cleaning off old paint, or the weathered surface of stonework; for
polishing up castings and forgings after they have been brazed. At the
cycle factory you will find the sand-jet hard at work on the joints
of cycle frames, which must be cleared of all roughness before they
are fit for the enameller. The writer, a few days before penning these
lines, watched a jet removing London grime from the face of a large
hotel. Down a side street stood a steam-engine busily compressing
air, which was led by long pipes to the jet, situated on some lofty
scaffolding. The rapidity with which the flying grains scoured off
smoke deposits attracted the notice of a large crowd, which gazed with
upturned heads at the whitened stones. A peculiarity about the jet
is that it proves much more effective on hard material than on soft,
as the latter, by offering an elastic surface, robs the sand of its
cutting power.

After merely mentioning the _pneumatic rammer_ for forcing sand into
foundry moulds, we pass to the _pneumatic sand-papering_ machine,
which may be described briefly as a revolving disc carrying a circle
of sand-paper on its face revolved between guards which keep it flat
to its work. The disc flies round many hundreds of times per minute,
rapidly wearing down the fibrous surface of the wood it touches.
When the coarse paper has done its work a finely-grained cloth is
substituted to produce the finish needful for painting.

CHAPTER V

THE PEDRAIL: A WALKING STEAM-ENGINE

Have you ever watched carefully a steam-roller's action on the road
when it is working on newly laid stones? If you have, you noticed that
the stones, gravel, etc., in front of the roller moved with a wave-like
motion, so that the engine was practically climbing a never-ending
hill. No wonder then that the mechanism of such a machine needs to be
very strong, and its power multiplied by means of suitable gearing.

Again, suppose that an iron-tyred vehicle, travelling at a rapid pace,
meets a large stone, what happens? Either the stone is forced into the
ground or the wheel must rise over it. In either case there will be a
jar to the vehicle and a loss of propulsive power. Do not all cyclists
know the fatigue of riding over a bumpy road--fatigue to both muscles
and nerves?

As regards motors and cycles the vibration trouble has been largely
reduced by the employment of pneumatic tyres, which _lap over_ small
objects, and when they strike large ones minimise the shock by their
buffer-like nature. Yet there is still a great loss of power, and
if pneumatic-tyred vehicles suffer, what must happen to the solid,
snorting, inelastic traction-engine? On hard roads it rattles and
bumps along, pulverising stones, crushing the surface. When soft ground
is encountered, in sink the wheels, because their bearing surface must
be increased until it is sufficient to carry the engine's weight. But
by the time that they are six inches below the surface there will be a
continuous vertical belt of earth six inches deep to be crushed down
incessantly by their advance.

How much more favourably situated is the railway locomotive or truck.
_Their_ wheels touch metal at a point but a fraction of an inch in
length; consequently there is nothing to hamper their progression. So
great is the difference between the rail and the road that experiment
has shown that, whereas a pull of from 8 to 10 lbs. will move a ton on
rails, an equal weight requires a tractive force of 50 to 100 lbs. on
the ordinary turnpike.

In order to obviate this great wastage of power, various attempts
have been made to provide a road locomotive with means for laying
its own rail track as it proceeds. About forty years ago Mr. Boydell
constructed a wheel which took its own rail with it, the rails being
arranged about the wheel like a hexagon round a circle, so that as the
wheel moved it always rested on one of the hexagon's sides, itself flat
on the ground. This device had two serious drawbacks. In the first
place, the plates made a rattling noise which has been compared to the
reports of a Maxim gun; secondly, though the contrivance acted fairly
well on level ground, it failed when uneven surfaces were encountered.
Thus, if a brick lay across the path, one end of a plate rested on the
brick, the other on the ground behind, and the unsupported centre
had to carry a sudden, severe strain. Furthermore, the plates, being
connected at the angles of the hexagon, could not tilt sideways, with
the result that breakages were frequent.

Of late years another inventor, Mr. J. B. Diplock, has come forward
with an invention which bids fair to revolutionise heavy road traffic.
At present, though it has reached a practical stage and undergone many
tests satisfactorily, it has not been made absolutely perfect, for the
simple reason that no great invention jumps to finality all at once.
Are not engineers still improving the locomotive?

The Pedrail, as it has been named, signifies a rail moving on feet.
Mr. Diplock, observing that a horse has for its weight a tractive
force much in excess of the traction-engine, took a hint from nature,
and conceived the idea of copying the horse's foot action. The reader
must not imagine that here is a return to the abortive and rather
ludicrous attempts at a walking locomotive made many years ago, when
some engineers considered it proper that a railway engine should be
_propelled_ by legs. Mr. Diplock's device not merely propels, but
also steps, _i.e._ selects the spot on the ground which shall be the
momentary point at which propulsive force shall be exerted. To make
this clearer, consider the action of a wheel. First, we will suppose
that the spokes, any number you please, are connected at their outer
ends by flat plates. As each angle is passed the wheel falls flop on to
the next plate. The greater the number of the spokes, the less will be
each successive jar (or step); and consequently the perfect wheel is
theoretically one in which the sides have been so much multiplied as
to be infinitely short.

A horse has practically two wheels, its front legs one, its back legs
the other. The shoulder and hip joints form the axles, and the legs
the spokes. As the animal pulls, the leg on the ground advances at the
shoulder past the vertical position, and the horse would fall forwards
were it not for the other leg which has been advanced simultaneously.
Each step corresponds to our many-sided wheel falling on to a flat
side--and the "hammer, hammer, hammer on the hard high road" is the
horsey counterpart of the metallic rattle.

On rough ground a horse has a great advantage over a wheeled tractor,
because it can put its feet down _on the top_ of objects of different
elevations, and _still pull_. A wheel cannot do this, and, as we have
seen, a loss of power results. Our inventor, therefore, created in his
pedrail a compromise between the railway smoothness and ease of running
and the selective and accommodating powers of a quadruped.

We must now plunge into the mechanical details of the pedrail, which
is, strictly speaking, a term confined to the wheel alone. Our
illustration will aid the reader to follow the working of the various
parts.

In a railway we have (a) sleepers, on the ground, (b) rails
attached to the sleepers, (c) wheels rolling over the rails. In the
pedrail the order, reckoning upwards, is altered. On the ground is the
_ped_, or movable sleeper, carrying wheels, over which a rail attached
to the moving vehicle glides continuously. The _principle_ is used by
anyone who puts wooden rollers down to help him move heavy furniture
about.

Of course, the peds cannot be put on the ground and left behind; they
must accompany their rollers and rails. We will endeavour to explain in
simple words how this is effected.

To the axles of the locomotive is attached firmly a flat, vertical
plate, parallel to the sides of the fire-box. Pivoted to it, top and
bottom, at their centres, are two horizontal rocking arms; and these
have their extremities connected by two bow-shaped bars, or cams, their
convex edges pointing outwards, away from the axle. Powerful springs
also join the rocking arms, and tend to keep them in a horizontal
position. Thus we have a powerful frame, which can oscillate up and
down at either end. The bottom arm is the rail on which the whole
weight of the axle rests.

The rotating and moving parts consist of a large, flat, circular
case, the sides of which are a few inches apart. Its circumference is
pierced by fourteen openings, provided with guides, to accommodate as
many short sliding spokes, which are in no way attached to the main
axle. Each spoke is shaped somewhat like a tuning-fork. In the V is a
roller-wheel, and at the tip is a "ped," or foot. As the case revolves,
the tuning-fork spokes pass, as it were, with a leg on each side of
the framework referred to above; the wheel of each spoke being the
only part which comes into contact with the frame. Strong springs hold
the spokes and rollers normally at an equal distance from the wheel's
centre.

It must now be stated that the object of the framework is to thrust
the rollers outwards as they approach the ground, and slide them below
the rail. The side-pieces of the frame are, as will be noticed (see
Fig. 3), eccentric, _i.e._ points on their surfaces are at different
distances from the axle centre. This is to meet the fact that the
distance from the axle to the ground is greater in an oblique direction
than it is vertically, and therefore for three spokes to be carrying
the weight at once, two of them must be more extended than the third.
So then a spoke is moved outward by the frame till its roller gets
under the rail, and as it passes off it it gradually slides inwards
again.

It will be obvious to the reader that, if the "peds" were attached
inflexibly to the ends of their spokes they would strike the ground at
an angle, and, of course, be badly strained. Now, Mr. Diplock meant
his "peds" to be as like feet as possible, and come down _flat_. He
therefore furnished them with ankles, that is, ball-and-socket joints,
so that they could move loosely on their spokes in all directions;
and as such a contrivance must be protected from dust and dirt, the
inventor produced what has been called a "crustacean joint," on account
of the resemblance it bears to the overlapping armour-plates of a
lobster's tail. The plates, which suggest very thin quoits, are made of
copper, and can be renewed at small cost when badly worn. An elastic
spring collar at the top takes up all wear automatically, and renders
the plates noiseless. This detail cost its inventor much work. The
first joint made represented an expenditure of £6; but now, thanks to
automatic machinery, any number can be turned out at 3s. 6d. each.

A word about the feet. A wheel has fourteen of these. They are eleven
inches in diameter at the tread, and soled with rubber in eight
segments, with strips of wood between the segments to prevent suction
in clay soil. The segments are held together by a malleable cast-iron
ring around the periphery of the feet and a tightening core in the
centre. These wearing parts, being separate from the rest of the foot,
are easily and cheaply renewed, and repairs can be quickly effected,
if necessary, when on the road. The surface in contact with the ground
being composed of the three substances--metal, wood, and rubber, which
all take a bearing, provides a combination of materials adapted to the
best adhesion and wear on any class of road, or even on no road at all.

[Illustration: FIG. 3]

Motive power is transmitted by the machinery to the wheel axle, from
that to the casing, from the casing to the sliding spokes. As there
are alternately two and three feet simultaneously in contact with the
ground, the power of adhesion is very great--much greater than that
of an ordinary traction-engine. This is what Professor Hele-Shaw says
in a report on a pedrail tractor: "The weight of the engine is spread
over no less than twelve feet, each one of which presses upon the
ground with an area immensely greater--probably as much as ten times
greater--than that of all the wheels (of an ordinary traction-engine)
taken together on a hard road. Upon a soft road all comparison between
wheels and the action of these feet ceases. The contact of each of the
feet of the Pedrail is absolutely free from all slipping action, and
attains the absolute ideal of working, being merely placed in position
without sliding to take up the load, and then lifted up again without
any sliding to be carried to a new position on the road."

It is necessary that the feet should come down flat on the ground.
If they struck it at all edgeways they would "sprain their ankles";
otherwise, probably break off at the ball joint. Mechanism was,
therefore, introduced by which the feet would be turned over as they
approached the ground, and be held at the proper angle ready for the
"step." Without the aid of a special diagram it would be difficult to
explain in detail how this is managed; and it must suffice to say that
the chief feature is a friction-clutch worked by the roller of the
foot's spoke.

To the onlooker the manner in which the pedrail crawls over obstacles
is almost weird. The writer was shown a small working model of a
pedrail, propelled along a board covered with bits of cork, wood, etc.
The axle of the wheel scarcely moved upwards at all, and had he not
actually seen the obstacles he would have been inclined to doubt their
existence. An ordinary wheel of equal diameter took the obstructions
with a series of bumps and bounds that made the contrast very striking.

[Illustration: FIG. 4]

An extreme instance of the pedrail's capacity would be afforded by the
ascent of a flight of steps (see Fig. 4). In such a case the three
"peds" carrying the weight of an axle would not be on the same level.
That makes no difference, because the frame merely tilts on its top
and bottom pivots, the front of the rail rising to a higher level than
the back end, and the back spokes being projected by the rail much
further than those in front, so that the engine is simply levered over
its rollers up an inclined plane. Similarly, in descending, the front
spokes are thrust out the furthest, and the reverse action takes place.

With so many moving parts everything must be well lubricated, or the
wear would soon become serious. The feet are kept properly greased
by being filled with a mixture of blacklead and grease of suitable
quality, which requires renewal at long intervals only. The sliding
spokes, rollers, and friction-clutches are all lubricated from one
central oil-chamber, through a beautiful system of oil-tubes, which
provides a circulation of the oil throughout all the moving parts. The
central oil-chamber is filled from one orifice, and holds a sufficient
supply of oil for a long journey.

We may now turn for a moment from the pedrail itself to the vehicles
to which it is attached. Here, again, we are met by novelties, for in
his engines Mr. Diplock has so arranged matters, that not only can
both front and back pairs of wheels be used as drivers, but both also
take part in the steering. As may be imagined, many difficulties had
to be surmounted before this innovation was complete. But that it was
worth while is evident from the small space in which a double-steering
tractor can turn, thanks to both its axles being movable, and from the
increased power. Another important feature must also be noticed, viz.
that the axles can both tip vertically, so that when the front left
wheel is higher than its fellow, the left back wheel may be lower than
the right back wheel. In short, _flexibility_ and power are the ideals
which Mr. Diplock has striven to reach. How far he has been successful
may be gathered from the reports of experts. Professor Hele-Shaw,
F.R.S., says: "The Pedrail constitutes, in my belief, the successful
solution of a walking machine, which, whilst obviating the chief
objections to the ordinary wheel running upon the road, can be made
to travel anywhere where an ordinary wheel can go, and in many places
where it cannot. At the same time it has the mechanical advantages
which have made the railway system such a phenomenal success. It
constitutes, in my belief, the solution of one of the most difficult
mechanical problems, and deserves to be considered as an invention
quite apart from any particular means by which it is actuated, whether
it is placed upon a self-propelled carriage or a vehicle drawn by any
agency, mechanical or otherwise.... The way in which all four wheels
are driven simultaneously so as to give the maximum pulling effect
by means of elastic connection is in itself sufficient to mark the
engine as a most valuable departure from common practice. Hitherto this
driving of four wheels has never been successfully achieved, partly
because of the difficulty of turning the steering-wheels, and partly
because, until the present invention of Mr. Diplock, the front and hind
wheels would act against each other, a defect at first experienced and
overcome by the inventor in his first engine."

[Illustration: A PEDRAIL TRACTOR ENGAGED IN WAR OFFICE TRIALS

The inventor, Mr. J. B. Diplock, is standing on the left of the group.
Observe the manner in which the feet gradually assume a horizontal
position as they approach the ground.]

On January 8th, 1902, Mr. Diplock tried an engine fitted with two
ordinary wheels behind and two pedrails in front. The authority quoted
above was present at the trials, and his opinion will therefore be
interesting. "The points which struck me immediately were (1) the
marvellous ease with which it started into action, (2) the little
noise with which it worked.... Another thing which I noticed was the
difference in the behaviour of the feet and wheels. The feet did not
in any way seem to affect the surface of the road. Throwing down large
stones the size of the fist into their path, the feet simply set
themselves to an angle in passing over the stones, and did not crush
them; whereas, the wheel coming after invariably crushed the stones,
and, moreover, distorted the road surface.

"Coming to the top of the hill, I made the Pedrail walk first over
3-inch planks, then 6-inch, and finally over a 9-inch balk.... One
could scarcely believe, on witnessing these experiments, that the
whole structure was not permanently distorted and strained, whereas
it was evidently within the limits of play allowed by the mechanism.
As a proof of this the Diplock engine walked down to the works, and
I then witnessed its ascent of a lane, beside the engineering works,
which had ruts eight or ten inches deep, and was a steep slope. This
lane was composed in places of the softest mud, and whereas the
wheels squeezed out the ground in all directions, the feet of the
Pedrails set themselves at the angles of the rut where it was hard, or
walked through the soft and yielding mud without making the slightest
disturbance of the surrounding ground.... I came away from that
trial with the firm conviction that I had seen what I believe to be the
dawn of a new era in mechanical transport."

Mr. Diplock does not regard the pedrail as an end in itself so much as
a means to an end, viz. the development of road-borne traffic. For very
long distances which must be covered in a minimum of time the railway
will hold its own. But there is a growing feeling that unless the
railways can be fed by subsidiary methods of transport more effectively
than at present, and unless remote country districts, whither it
would not pay to carry even a light railway, are brought into closer
touch with the busier parts, our communications cannot be considered
satisfactory, and we are not getting the best value out of our roads.
For many classes of goods _cheapness_ of transportation is of more
importance than _speed_; witness the fact that coal is so often sent by
canal rather than by rail.

Here, then, is the chance for the pedrail tractor and its long train
of vehicles fitted with pedrail wheels, which will tend to improve the
road surfaces they travel over. Mr. Diplock sets out in his interesting
book, _A New System of Heavy Goods Transport on Common Roads_, a scheme
for collecting goods from "branch" routes on to "main" routes, where a
number of cars will be coupled up and towed by powerful tractors. With
ordinary four-wheeled trucks it is difficult to take a number round
a sharp corner, since each truck describes a more sudden circle than
its predecessor, the last often endeavouring to climb the pavement.
Four-wheeled would therefore be replaced by two-wheeled trucks,
provided with special couplings to prevent the cars tilting, while
allowing them to turn. Cars so connected would follow the same track
round a curve.

The body of the car would be removable, and of a standard size. It
could be attached to a simple horse frame for transport into the
fields. There the farmer would load his produce, and when the body was
full it would be returned to the road, picked up by a crane attached
to the tractor, swung on to its carriage and wheels, and taken away
to join other cars. By making the bodies of such dimensions as to fit
three into an ordinary railway truck, they could be entrained easily.
On reaching their destination another tractor would lift them out, fit
them to wheels, and trundle them off to the consumer. By this method
there would be no "breaking bulk" of goods required from the time it
was first loaded till it was exposed in the market for sale.

These things are, of course, in the future. Of more present importance
is the fact that the War Office has from the first taken great interest
in the new invention, which promises to be of value for military
transport over ground either rough or boggy. Trials have been made
by the authorities with encouraging results. That daring writer, Mr.
H. G. Wells, has in his _Land Ironclads_ pictured the pedrail taking
an offensive part in warfare. Huge steel-plated forts, mounted on
pedrails, and full of heavy artillery and machine guns, sweep slowly
across the country towards where the enemy has entrenched himself. The
forts are impervious alike to shell and bullet, but as they cross ditch
or hillock in their gigantic stride, their artillery works havoc among
their opponents, who are finally forced to an unconditional surrender.

Even if the pedrail is not made to carry weapons of destruction, we
can, after our experiences with horseflesh in the Boer War, understand
how important it may become for commissariat purposes. The feats which
it has already performed mark it as just the locomotive to tackle the
rough country in which baggage trains often find themselves.

To conclude with a more peaceful use for it. When fresh country is
opened up, years must often pass before a proper high road can be made,
yet there is great need of an organised system of transport. Whither
ordinary traction-engines, or carts, even horses, could scarcely
penetrate, the pedrail tractor, thanks to its big, flat feet, which
give it, as someone has remarked, the appearance of "a cross between a
traction-engine and an elephant," will be able to push its way at the
forefront of advancing civilisation.

At home we shall have good reason to welcome the pedrail if it frees us
from those terrible corrugated tracks so dreaded by the cyclist, and to
bless it if it actually beats our roads down into a greater smoothness
than they now can boast.

CHAPTER VI

INTERNAL COMBUSTION ENGINES

OIL ENGINES--ENGINES WORKED WITH PRODUCER GAS--BLAST FURNACE GAS ENGINES

If carbon and oxygen be made to combine chemically, the process is
accompanied by the phenomenon called _heat_. If heat be applied to a
liquid or gas in a confined space it causes a violent separation of its
molecules, and power is developed.

In the case of a steam-engine the fuel is coal (carbon in a more or
less pure form), the fluid, water. By burning the fuel under a boiler,
a gas is formed which, if confined, rapidly increases the pressure on
the walls of the confining vessel. If allowed to pass into a cylinder,
the molecules of steam, struggling to get as far as possible from
one another, will do useful work on a piston connected by rods to a
revolving crank.

We here see the combustion of fuel external to the cylinder, i.e. under
the boiler, and the fuel and fluid kept apart out of actual contact.
In the gas or oil-vapour engine the fuel is brought into contact with
the fluid which does the work, mixed with it, and burnt _inside_ the
cylinder. Therefore these engines are termed _internal combustion_
engines.

Supposing that a little gunpowder were placed in a cylinder, of which
the piston had been pushed almost as far in as it would go, and that
the powder were fired by electricity. The charcoal would unite with the
oxygen contained in the saltpetre and form a large volume of gas. This
gas, being heated by the ignition, would instantaneously expand and
drive out the piston violently.

A very similar thing happens at each explosion of an internal
combustion engine. Into the cylinder is drawn a charge of gas,
containing carbon, oxygen, and hydrogen, and also a proportion of air.
This charge is squeezed by the inward movement of the piston; its
temperature is raised by the compression, and at the proper moment it
is ignited. The oxygen and carbon seize on one another and burn (or
combine), the heat being increased by the combustion of the hydrogen.
The air atoms are expanded by the heat, and work is done on the piston.
But the explosion is much gentler than in the case of gunpowder.

During recent years the internal combustion engine has been making
rapid progress, ousting steam power from many positions in which it
once reigned supreme. We see it propelling vehicles along roads and
rails, driving boats through the water, and doing duty in generating
stations and smelting works to turn dynamos or drive air-pumps--not
to mention the thousand other forms of usefulness which, were they
enumerated here, would fill several pages.

A decade ago an internal combustion engine of 100 h.p. was a wonder;
to-day single engines are built to develop 3,000 h.p., and in a few
years even this enormous capacity will doubtless be increased.

It is interesting to note that the rival systems--gas and steam--were
being experimented with at the same time by Robert Street and James
Watt respectively. While Watt applied his genius to the useful
development of the power latent in boiling water, Street, in 1794, took
out letters patent for an engine to be worked by the explosions caused
by vaporising spirits of turpentine on a hot metal surface, mixing the
vapour with air in a cylinder, exploding the mixture, and using the
explosion to move a piston. In his, and subsequent designs, the mixture
was pumped in from a separate cylinder under slight pressure. Lenoir,
in 1860, conceived the idea of making the piston _suck_ in the charge,
so abolishing the need of a separate pump; and many engines built under
his patents were long in use, though, if judged by modern standards,
they were very wasteful of fuel. Two years later Alphonse Beau de
Rochas proposed the further improvement of utilising the cylinder, not
only as a suction pump, but also as a compressor; since he saw that a
compressed mixture would ignite very much more readily than one not
under pressure. Rochas held the secret of success in his grasp, but
failed to turn it to practical account. The "Otto cycle," invented by
Dr. Otto in 1876, is really only Rochas's suggestion materialised. The
large majority of internal combustion engines employ this "cycle" of
operations, so we may state its exact meaning:--

(1) A mixture of explosive gas and air is drawn into the cylinder by
the piston as it passes outwards (i.e. in the direction of the crank),
through the inlet valve.

(2) The valve closes, and the returning piston compresses the mixture.

(3) The mixture is fired as the piston commences its second journey
outwards, and gives the "power" stroke.

(4) The piston, returning again, ejects the exploded mixture through
the outlet or exhaust valve, which began to open towards the end of the
third stroke.

Briefly stated, the "cycle" is--suction, compression, explosion,
expulsion; one impulse being given during each cycle, which occupies
two complete revolutions of the fly-wheel. Since the first, second, and
third operations all absorb energy, the wheel must be heavy enough to
store sufficient momentum during the "power" stroke to carry the piston
through all its three other duties.

Year by year, the compression of the mixture has been increased, and
improvements have been made in the methods of governing the speed
of the engine, so that it may be suitable for work in which the
"load" is constantly varying. By doubling, trebling, and quadrupling
the cylinders the drive is rendered more and more steady, and the
elasticity of a steam-engine more nearly approached.

The internal combustion engine has "arrived" so late because in the
earlier part of last century conditions were not favourable to its
development. Illuminating gas had not come into general use, and such
coal gas as was made was expensive. The great oil-fields of America and
Russia had not been discovered. But while the proper fuels for this
type of motor were absent, coal, the food of the steam-engine, lay
ready to hand, and in forms which, though useless for many purposes,
could be advantageously burnt under a boiler.

Now the situation has altered. Gas is abundant; and oil of the right
sort costs only a few pence a gallon. Inventors and manufacturers
have grasped the opportunity. To-day over 3,000,000 h.p. is developed
continuously by the internal combustion engine.

Steam would not have met so formidable a rival had not that rival had
some great advantages to offer. What are these? Well, first enter a
factory driven by steam power, and carefully note what you see. Then
visit a large gas- or oil-engine plant. You will conclude that the
latter scores on many points. There are no stokers required. No boilers
threaten possible explosions. The heat is less. The dust and dirt are
less. The space occupied by the engines is less. There is no noisome
smoke to be led away through tall and expensive chimneys. If work
is stopped for an hour or a day, there are no fires to be banked or
drawn--involving waste in either case.

Above all, the gas engine is more efficient, or, if you like to express
the same thing in other words, more economical. If you use only one
horse-power for one hour a day, it doesn't much matter whether that
horse-power-hour costs 4d. or 5d. But in a factory where a thousand
horse-power is required all day long, the extra pence make a big
total. If, therefore, the proprietor finds that a shilling's-worth of
gas or oil does a quarter as much work again as a shilling's-worth of
coal, and that either form of fuel is easily obtained, you may be sure
that, so far as economy is concerned, he will make up his mind without
difficulty as to the class of engine to be employed. A pound of coal
burnt under the best type of steam-engine gives but 10 per cent. of its
heating value in useful work. A good oil-engine gives 20-25 per cent.,
and in special types the figures are said to rise to 35-40 per cent.
We may notice another point, viz. that, while a steam-engine must be
kept as hot as possible to be efficient, an internal combustion engine
must be cooled. In the former case no advantage, beyond increased
efficiency, results. But in the latter the water passed round the
cylinders to take up the surplus heat has a value for warming the
building or for manufacturing processes.

Putting one thing with another, experts agree that the explosion engine
is the prime mover of the future. Steam has apparently been developed
almost to its limit. Its rival is but half-grown, though already a
giant.

Some internal combustion engines use petroleum as their fuel,
converting it into gas before it is mixed with air to form the charge;
others use coal-gas drawn from the lighting mains; "poor gas" made in
special plants for power purposes; or natural gas issuing from the
ground. Natural gas occurs in very large quantities in the United
States, where it is conveyed through pipes under pressure for hundreds
of miles, and distributed among factories and houses for driving
machinery, heating, and cooking. In England and Europe the petroleum
engine and coal-gas engine have been most utilised; but of late the
employment of smelting-furnace gases--formerly blown into the air
and wasted--and of "producer" gas has come into great favour with
manufacturers. The latest development is the "suction" gas engine,
which makes its own gas by drawing steam and air through glowing fuel
during the suction stroke.

We will consider the various types under separate headings devoted

(1) To the oil-fuel engine,

(2) The producer-gas engine and the suction-gas engine,

(3) Blast-furnace gas engines, with reference to the installations used
in connection with the last two.

All explosion engines (excepting the very small types employed on motor
cycles) have a water-jacket round the cylinders to absorb some of the
heat of combustion, which would otherwise render the metal so hot as to
make proper lubrication impossible, and also would unduly expand the
incoming charge of gas and air before compression. The ideal engine
would take in a full charge of cold mixture, which would receive no
heat from the walls of the cylinder, and during the explosion would
pass no heat through the walls. In other words, the ideal metal for the
cylinders would be one absolutely non-receptive of heat. In the absence
of this, engineers are obliged to make a compromise, and to keep the
cylinder at such a temperature that it can be lubricated fittingly,
while not becoming so cold as to absorb _too much_ of the heat of
explosion.

OIL ENGINES

These fall into two main classes:--

(a) Those using light, volatile, mineral oils--such as petrol and
benzoline--and alcohol, a vegetable product.

(b) Those using heavy oils, such as paraffin oil (kerosene) and the
denser constituents of rock-oil left in the stills after the kerosene
has been driven off. American petroleum is rich in burning-oil and
petrol; Russian in the very heavy residue, called _astakti_. Given the
proper apparatus for vaporisation, mineral oils of any density can be
used in the explosion engine.

The first class is so well known as the mover of motor vehicles and
boats that we need not linger here on it. It may, however, be remarked
that engines using the easily-vaporised oils are not of large powers,
since the fuel is too expensive to make them valuable for installations
where large units of power are needed. They have been adopted for
locomotives on account of their lightness, and the ease with which they
can be started. Petrol vaporises at ordinary temperatures, so that air
merely passed over the spirit absorbs sufficient vapour to form an
explosive mixture. The "jet" carburetter, now generally employed, makes
the mixture more positive by atomising the spirit as it passes through
a very fine nozzle into the mixing chamber under the suction from the
cylinder. On account of their small size spirit engines work at very
high speeds as compared with the large oil or gas engine. Thus, while
a 2,000 h.p. Körting gas engine develops full power at eighty-five
revolutions a minute, the tiny cycle motor must be driven at 2,000 to
3,000 revolutions. Speaking generally, as the size increases the speed
decreases.

Of heavy oil engines there are some dozens of well-tried types. They
differ in their methods of effecting the following operations.

  1. The feeding of the oil fuel to the engine.
  2. The conversion of the oil into vapour.
  3. The ignition of the charge.
  4. The governing of speed.

All these engines have a vaporiser, or chamber wherein the oil is
converted into gas by the action of heat. When starting-up the engine,
this chamber must be heated by a specially designed lamp, similar in
principle to that used by house painters for burning old paint off wood
or metal.

Let us now consider the operations enumerated above in some detail.

1. _The oil supply._ Fuel is transferred from the storage tank to the
vaporiser either by the action of gravity through a regulating device
to prevent "flooding," or by means of a small pump, or by the suction
of the piston, which _lifts_ the liquid. In some engines the air and
gas enter the cylinder through a single valve; in others through
separate valves.

2. _Vaporisation._ As already remarked, the vaporising chamber must be
heated to start the engine. When work has begun the lamp may be removed
if the engine is so designed that the chamber stores up sufficient heat
in its walls from each explosion to vaporise the charge for the next
power stroke. The Crossley engine has a lamp continuously burning; the
Hornsby-Ackroyd depends upon the storage of heat from explosions in a
chamber opening into the cylinder. The best designs are fairly equally
divided between the two systems.

3. _Ignition_ of the compressed charge is effected in one of four ways:
by bringing the charge, at the end of the compression stroke, into
contact with a closed tube projecting from the cylinder and heated
outside by a continuously burning lamp; by the heat stored in some
part of the combustion chamber (_i.e._ that portion of the cylinder
not swept by the piston); by an electric spark; or by the mere heat of
compression. The second and third methods are confined to comparatively
few makes; and the Diesel Oil Engine (of which more presently) has a
monopoly of the fourth.

4. _Governing._ All engines which turn machinery doing intermittent
work--such as that of a sawmill, or electric generating plant
connected with a number of motors--must be very carefully guarded from
overrunning. Imagine the effect on an engine which is putting out its
whole strength and getting full charges of fuel, if the belt suddenly
slipped off and it were "allowed its head." A burst fly-wheel would be
only one of the results. The steam-engine is easily controlled by the
centrifugal action of a ball-governor, which, as the speed increases,
gradually spreads its balls and lifts a lever connected with a valve
in the steam supply pipe. Owing to its elastic nature, steam will do
useful work if admitted in small quantities to the cylinder. But a
difficulty arises with the internal combustion engine if the _supply_
of mixture is similarly throttled, because a loss of quantity means
loss of compression and bad ignition. Many oil engines are therefore
governed by apparatus which, when the speed exceeds a certain limit,
cuts off the supply altogether, either by throwing the oil-pump
temporarily out of action, or by lifting the exhaust valve so that the
movement of the piston causes no suction--the "hit-and-miss" method, as
it is called.

The means adopted depends on the design of the engine; and it must
be said that, though all the devices commonly used effect their
purpose, none are perfect; this being due rather to the nature of an
internal explosion engine than to any lack of ingenuity on the part of
inventors. The steadiest running is probably given with the throttle
control, which diminishes the supply. On motor cars this method has
practically ousted the "hit-and-miss" governed exhaust valve; but
in stationary engines we more commonly find the speed controlled by
robbing the mixture of the explosive gas in inverse proportion to the
amount of the work required from the engine.

THE DIESEL OIL ENGINE,

on account of some features peculiar to it, is treated separately.
In 1901 an expert wrote of it that "the engine has not attained any
commercial position." Herr Rudolph Diesel, the inventor, has, however,
won a high place for his prime-mover among those which consume liquid
fuel, on account of its extraordinary economy. The makers claim--as the
result of many tests--that with the crude rock-oil (costing in bulk
about 2d. a gallon) which it uses, a horse-power can be developed for
one hour by this engine for _one-tenth of a penny_. The daily fuel bill
for a 100 h.p. engine running ten hours per day would therefore be 8s.
4d. To compete with the Diesel engine a steam installation would have
to be of the very highest class of triple-expansion type, of not less
than 400 h.p., and using every hour per horse-power only 1-3/4 lbs. of
coal at 9s. per ton. Very few large steam-engines work under conditions
so favourable, and with small sizes 3-4 lbs. of coal would be burnt for
every "horse-power-hour."

The Diesel differs from other internal combustion engines in the
following respects:--

  1. It works with very much higher compression.
  2. The ignition is spontaneous, resulting from the high
      compression of the charge alone.
  3. The fuel is not admitted into the cylinder until the
      power-stroke begins, and enters in the form of a
      fine spray.
  4. The combustion of the fuel is much slower, and therefore
      gives a more continuous and elastic push to the
      piston.

The engine works on the ordinary Otto cycle. To start it, air
compressed in a separate vessel is injected into the cylinder. The
piston flies out, and on its return squeezes the air to about 500 lbs.
to the square inch, thus rendering it incandescent.[11] Just as the
piston begins to move out again a valve in the cylinder-head opens, and
a jet of pulverised oil is squirted in by air compressed to 100 lbs.
per square inch more than the pressure in the cylinder. The vapour,
meeting the hot air, burns, but comparatively slowly: the pressure in
the cylinder during the stroke decreasing much more gradually than in
other engines. Governing is effected by regulation of the amount of oil
admitted into the cylinder.

In spite of its high compression this engine runs with very little
vibration. The writer saw a penny stand unmoved on its edge on the top
of a cylinder in which the piston was reciprocating 500 times a minute!

ENGINES WORKED BY PRODUCER-GAS

These engines are worked by a special gas generated in an apparatus
called a "producer." If air is forced through incandescent carbon in
a closed furnace its oxygen unites with the carbon and forms carbonic
acid gas, known chemically as CO_{2}, because every molecule of the
gas contains one atom of carbon and two of oxygen. This gas, being
the product of combustion, cannot burn (_i.e._ combine with more
oxygen), but as it passes up through the glowing coke, coal, or other
fuel, it absorbs another carbon atom into every molecule, and we have
C_{2}O_{2}, or 2 CO, which we know as _carbon monoxide_. This gas may
be seen burning on the top of an open fire with a very pale blue flame,
as it once more combines with oxygen to form carbonic acid gas.

The carbon monoxide is valuable as a heating agent, and when mixed with
air forms an explosive mixture.

If along with the air sent into our furnace there goes a proportion
of steam, further chemical action results. The oxygen of the steam
combines with carbon to form carbon monoxide, and sets free the
hydrogen. The latter gas, when it combines with oxygen in combustion,
causes intense heat; so that if from the furnace we can draw off carbon
monoxide and hydrogen, we shall be able to get a mixture which during
combustion will set up great heat in the cylinder of an engine.

In 1878 Mr. Emerson Dowson invented an apparatus for manufacturing
a gas suitable for power plant, the gas being known as Producer or
Poor Gas, the last term referring to its poorness in hydrogen as
compared with coal and other gases. While the hydrogen is a desirable
ingredient in an explosive charge, it must not form a large proportion,
since under compression it renders the mixture in which it takes part
dangerously combustible, and liable to spontaneous ignition before the
piston has finished the compression stroke. Water-gas, very rich in
hydrogen, and made by a very similar process, is therefore not suitable
for internal combustion engines.

There are many types of producers, but they fall under two main heads,
_i.e._ the _pressure_ and the _suction_.

The _pressure_ producer contains the following essential parts:--

The _generator_, a vertical furnace fed from the top through an
air-tight trap, and shut off below from the outside atmosphere by
having its foot immersed in water. Any fuel or ashes which fall through
the bars into the water can be abstracted without spoiling the draught.
Air and steam are forced into the generator, and pass up through the
fuel with the chemical results already described. The gases then flow
into a _cooler_, enclosed in a water-jacket, through which water
circulates, and on into a _scrubber_, where they must find their way
upwards through coke kept dripping with water from overhead jets. The
water collects impurities of all sorts, and the gas is then ready for
storage in the gas-holders or for immediate use in the engines.

A pound of anthracite coal thus burnt will yield enough gas to develop
1 h.p. for one hour.

_Suction Gas Plants._--With these gas is not stored in larger
quantities than are needed for the immediate work of the engine. In
fact, the engine itself during its suction strokes _draws_ air and
steam through a very small furnace, coolers, and scrubbers direct into
the cylinder. The furnace is therefore fed with air and water, not
by pressure from outside, but by suction from inside, hence the name
"suction producer." At the present time suction gas engines are being
built for use on ships, since a pound of fuel thus consumed will drive
a vessel further than if burnt under a steam boiler. Very possibly the
big ocean liners of twenty years hence may be fitted with such engines
in the place of the triple and quadruple expansion steam machinery now
doing the work.

BLAST-FURNACE GAS ENGINES

Every iron blast-furnace is very similar in construction and action
to the generator of a producer-gas plant. Into it are fed through
a hopper, situated in the top, layers of ore, coal or coke, and
limestone. At the bottom enters a blast of air heated by passing
through a stove of firebrick raised to a high temperature by the carbon
monoxide gas coming off from the furnace. When the stove has been
well heated the gas supply is shut off from it and switched to the
engine-house to create power for driving the huge blowers.

The gas contains practically no hydrogen, as the air sent through
the furnace is dry; but since it will stand high compression, it is
very suitable for use in large engines. Formerly all the gas from the
furnace was expelled into the open air and absolutely wasted; then
it was utilised to heat the forced draught to the furnace; next, to
burn under boilers; and last of all, at the suggestion of Mr. B. H.
Thwaite, to operate internal combustion engines for blowing purposes.
Thus, in the fitness of things, we now see the biggest gas engines in
the world installed where gas is created in the largest quantities, and
an interesting cycle of actions results. The engine pumps the air; the
air blows the furnace and melts the iron out of the ore; the furnace
creates the gas; the gas heats the air or works the engines to pump
more air. So engines and furnace mutually help each other, instead of
all the obligation being on the one side.

When, a few years ago, the method was first introduced, engines were
damaged by the presence of dust carried with the gas from the furnace.
Mr. B. H. Thwaite has, however, perfected means for the separation of
injurious matter, and blast-furnace gas is coming into general use in
England and on the Continent. Some idea of the power which has been
going to waste in ironworks for decades past may be gathered from a
report of Professor Hubert after experiments made in 1900. He says that
engines of large size do not use more than 100 cubic feet of average
blast-furnace gas per effective horse-power-hour, which is less than
one-fourth of the consumption of gas required to develop the same power
from boilers and good modern condensing steam-engines, so that there
is an immense surplus of power to be obtained from a blast-furnace
if the blowing engines are worked by the gas it generates, a surplus
which can be still further increased if the gas is properly cleaned.
It is estimated that for every 100 tons of coke used in an ordinary
Cleveland blast-furnace, after making ample allowance for gas for the
stoves and power for the lifts, pumps, etc., and for gas for working
the necessary blowing engines, there is a surplus of at least _1,500
h.p._; so that by economising gas by cleaning, and developing the
necessary power by gas engines, every furnace owner would have a very
large surplus of power for his steel or other works, or for selling in
the form of electricity or otherwise.

Yet all this gas had been formerly turned loose for the breezes to warm
their fingers at! Truly, as an observant writer has recorded, the sight
of a special plant being put up near a blast furnace to manufacture gas
for the blowing engines suggests the pumping of water uphill in order
to get water-power!

Messrs. Westgarth and Richardson, of Middlesbrough; the John Cockerill
Company, of Seraing, Belgium; and the De la Vergne Company, of New
York, are among the chief makers of the largest gas engines in the
world, ranging up to 3,750 h.p. each. These immense machines, some with
fly-wheels 30 feet in diameter, and cylinders spacious enough for a man
to stand erect in, work blowers for furnaces or drive dynamos. At the
works of the manufacturers mentioned the engines helped to make the
steel, and turn the machinery for the creation of brother monsters.

[Illustration: GIGANTIC GAS ENGINES

Five of sixteen 2,000 h.p. Körting Gas Engines built by the De la
Vergne Company of New York City for blowing the blast furnaces of the
Lackawanna Steel Company. The gas-engine plant at these works is the
largest in the world. Notice the man to the left.]

This use of a "bye-product" of industry is remarkable, but it can be
paralleled. Furnace slag, once cast away as useless, is now recognised
to be a valuable manure, or is converted into bricks, tiles, cement,
and other building materials. Again, the former waste from the coal-gas
purifier assumes importance as the origin of aniline dyes, creosote,
saccharine, ammonia, and oils. We really appear to be within sight of
the happy time when waste will be unknown. And it therefore is curious
that we still burn gas as an illuminant, when the same, if made to work
an engine, would give more lighting power in the shape of electric
current supplying incandescent lamps.

FOOTNOTE:

[11] The fact that air is heated to combustion point by compression has
long been known to the Chinese. In _The River of Golden Sand_, Captain
Gill writes: "The natives have an apparatus by which they strike a
light by compressed air. The apparatus consists of a wooden cylinder
2-1/2 inches long by 3/4 inch in diameter. This is closed at one end;
the bore being about the size of a stout quill pen, an air-tight piston
fits into this with a large flat knob at the top. The other end of the
piston is slightly hollowed out, and a very small piece of tinder is
placed on the top thus formed. The cylinder is held in one hand, the
piston inserted and pushed about half-way down; a very sharp blow is
then delivered with the palm of the hand on to the top of the knob; the
hand must at the same time close on the knob, and instantly withdraw
the piston, when the tinder will be found alight. The compression of
the air produces heat enough to light the tinder; but this will go out
again unless the piston is withdrawn very sharply. I tried a great many
times, but covered myself with confusion in fruitless efforts to get a
light, for the natives never miss it."

CHAPTER VII

MOTOR-CARS

THE MOTOR OMNIBUS--RAILWAY MOTOR-CARS

The development of the motor-car has been phenomenal. Early in 1896
the only mechanically moved vehicles to be seen on our roads were
the traction-engine, preceded by a man bearing a red flag, the
steam-roller, and, in the towns, a few trams. To-day the motor is
apparent everywhere, dodging through street traffic, or raising the
dust of the country roads and lanes, or lumbering along with its load
of merchandise at a steady gait.

As a purely speed machine the motor-car has practically reached its
limit. With 100 h.p. or more crowded into a vehicle scaling only a
ton, the record rate of travel has approached two miles in a minute on
specially prepared and peculiarly suitable tracks. Even up steep hills
such a monster will career at nearly eighty miles an hour.

Next to the racing car comes the touring car, engined to give sixty
miles an hour on the level in the more powerful types, or a much lower
speed in the car intended for quieter travel, and for people who are
not prepared to face a big bill for upkeep. The luxury of the age has
invaded the design of automobiles till the gorgeously decorated and
comfortably furnished Pullman of the railway has found a counterpart
in the motor caravan with its accommodation for sleeping and feeding.
While the town dweller rolls along in electric landaulet, screened
from wind and weather, the tourist may explore the roads of the world
well housed and lolling at ease behind the windows of his 2,000-guinea
machine, on which the engineer and carriage builder have lavished their
utmost skill.

The taunt of unreliability once levelled--and with justice--at the
motor-car, is fast losing its force, owing to the vast improvements in
design and details which manufacturers have been stimulated to make.
The motor-car industry has a great future before it, and the prizes
therein are such as to tempt both inventor and engineer. Every week
scores of patents are granted for devices which aim at the perfection
of some part of a car, its tyres, its wheels, or its engines. Until
standard types for all grades of motor vehicles have been established,
this restless flow of ideas will continue. Its volume is the most
striking proof of the vitality of the industry.

The uses to which the motor vehicle has been put are legion. On
railways the motor carriage is catering for local traffic. On the roads
the motor omnibus is steadily increasing its numbers. Tradesmen of all
sorts, and persons concerned with the distribution of commodities,
find that the petrol- or steam-moved car or lorry has very decided
advantages over horse traction. Our postal authorities have adopted the
motor mail van. The War Office looks to the motor to solve some of its
transportation difficulties. In short, the "motor age" has arrived,
which will, relatively to the "railway age," play much the same part
as that epoch did to the "horse age." At the ultimate effects of the
change we can only guess; but we see already, in the great acceleration
of travel wherever the motor is employed, that many social institutions
are about to be revolutionised. But for the determined opposition in
the 'thirties of last century to the steam omnibus we should doubtless
live to-day in a very different manner. Our population would be
scattered more broadcast over the country instead of being herded in
huge towns. Many railways would have remained unbuilt, but our roads
would be kept in much better condition, special tracks having been
built for the rapid travel of the motor. We have only to look to a
country now in course of development to see that the road, which leads
everywhere, will, in combination with the motor vehicle, eventually
supplant, or at any rate render unnecessary, the costly network of
railways which must be a network of very fine mesh to meet the needs of
a civilised community.

In the scope of a few pages it is impossible to cover even a tithe of
the field occupied by the ubiquitous motor-car, and we must, therefore,
restrict ourselves to a glance at the manufacture of its mechanism, and
a few short excursions into those developments which promise most to
alter our modes of life.

We will begin with a trip over one of the largest motor factories in
the world, selecting that of Messrs. Dion and Bouton, whose names are
inseparable from the history of the modern motor-car. They may justly
claim that to deal with the origin, rise, and progress of the huge
business which they have built up would be to give an account, in its
general lines, of all the phases through which the motor, especially
the petrol motor, has passed from its crudest shape to its present
state of comparative perfection.

The Count Albert de Dion was, in his earlier days, little concerned
with things mechanical. He turned rather to the fashionable pursuit of
duelling, in which he seems to have made a name. But he was not the man
to waste his life in such inanities, and when, one day, he was walking
down the Paris boulevards, his attention was riveted by a little
clockwork carriage exposed for sale among other New Year's gifts. That
moment was fraught with great consequences, for an inventive mind had
found a proper scope for its energy. Why, thought he, could not real
cars be made to run by some better form of motive power? On inquiring
he learnt that a workman named Bouton had produced the car. The Count,
therefore, sought the artisan; with whom he worked out the problem
which had now become his aim in life. Hence it is that the names
"Dion--Bouton" are found on thousands of engines all over the world.

The partners scored their first successes with steam- and petrol-driven
tricycles, built in a small workshop in the Avenue Malakoff in Paris.
The works were then transferred to Puteaux, which has since developed
into the great automobile centre of the world, and after two more
changes found a resting-place on the Quai National. Here close upon
3,000 hands are engaged in supplying the world's requirements in motors
and cars. Let us enter the huge block of buildings and watch them at
work.

The drawing-office is the brain of the factory. Within its walls new
ideas are being put into practical shape by skilled draughtsmen. The
drawings are sent to the model-making shop, where the parts are first
fashioned in wood. The shop contains dozens of big benches, circular
saws, and planing machines, one of them in the form of a revolving drum
carrying a number of planes, which turns thousands of times a minute,
and shapes off the rough surface of the blocks of hard wood as if it
were so much clay. These blocks are cut, planed, and turned, and then
put into the hands of a remarkably skilled class of workmen, who, with
rule, calliper, and chisel, shape out cylinders and other parts to the
drawings before them with wonderful patience and exactness.

After the model has been fashioned, the next step is to make a
clay mould from the same, with a hole in the top through which the
molten metal is poured. The foundry is most picturesque in a lurid,
Rembrandtesque fashion: "It is black everywhere. The floor, walls, and
roof are black, and the foundry hands look like unwashed penitents
in sackcloth and ashes. At the end of the building there is a raised
brickwork, and when the visitor is able to see in the darkness, he
distinguishes a number of raised lids along the top, while here and
there are strewn about huge iron ladles like buckets. On the foreman
giving the word, a man steps up on the brickwork and removes the lid,
when a column of intense white light strikes upwards. It gives one
the impression of coming from the bowels of the earth, like a hole
opening out in a volcano. The man bestrides the aperture, down which
he drops the ladle at the end of a long pole, and then pulling it up
again full of a straw-coloured, shining liquid, so close to him that we
shudder at the idea of its spilling over his legs and feet, he pours
the molten metal into a big ladle, which is seized by two men who pour
the liquid into the moulds. The work is more difficult than it looks,
for it requires a lot of practice to fill the moulds in such a way as
to avoid blow-holes and flaws that prove such a serious item in foundry
practice."

In the case-hardening department, next door, there are six huge ovens
with sliding fronts. Therein are set parts which have been forged or
machined, and are subjected to a high temperature while covered in
charcoal, so that the skin of the metal may absorb carbon at high
temperatures and become extremely tough. All shafts, gears, and other
moving parts of a car are subjected to this treatment, which permits
a considerable reduction in the weight of metal used, and greatly
increases its resistance to wear. After being "carbonised," the
material is tempered by immersion in water while of a certain heat,
judged by the colour of the hot metal.

We now pass to the turning-shop, where the cylinders are bored out
by a grinding disc rapidly rotating on an eccentric shaft, which is
gradually advanced through the cylinder as it revolves. The utmost
accuracy, to the 1/10,000 part of an inch, is necessary in this
operation, since the bore must be perfectly cylindrical, and also of a
standard size, so that any standard piston may exactly fit it. After
being bored, or rather ground, the walls of the cylinder are highly
polished, and the article is ready for testing. The workman entrusted
with this task hermetically closes the ends by inserting the cylinder
between the plates of an hydraulic press, and pumps in water to a
required pressure. If there be the slightest crack, crevice, or hole,
the water finds its way through, and the piece is condemned to the
rubbish heap.

In the "motor-room" are scores of cylinders, crank-cases, and gears
ready for finishing. Here the outside of bored cylinders is touched up
by files to remove any marks and rough projections left by the moulds.
The crank-cases of aluminium are taken in hand by men who chisel the
edges where the two halves fit, chipping off the metal with wonderful
skill and precision. The edges are then ground smooth, and after the
halves have been accurately fitted, the holes for the bolts connecting
them are drilled in a special machine, which presents a drill to each
hole in succession.

Having seen the various operations which a cylinder has to go through,
we pass into another shop given up to long lines of benches where
various motor parts are being completed. Each piece, however small,
is treated as of the utmost importance, since the failure of even
a tiny pin may bring the largest car to a standstill. We see a man
testing pump discs against a standard template to prove their absolute
accuracy. Close by, another man is finishing a fly-wheel, chipping
off specks of metal to make the balance true. We now understand
that machine tools cannot utterly displace the human hand and eye.
The fitters, with touches of the file, remove matter in such minute
quantities that its removal might seem of no consequence. But "matter
in the wrong place" is the cause of many breakdowns.

We should naturally expect that engines cast from the same pattern,
handled by the same machines, finished by the same men, would give
identical results. But as two bicycles of similar make will run
differently, so do engines of one type develop peculiarities. The
motors are therefore taken into a testing-room and bolted to two
rows of benches, forty at a time. Here they run under power for long
periods, creating a deafening uproar, until all parts work "sweetly."
The power of the engines is tested by harnessing them to dynamos and
noting the amount of current developed at a certain speed.

We might linger in the departments where accumulators, sparking plugs,
and other parts of the electrical apparatus of a car are made, or in
the laboratory where chemists pry into the results of a new alloy,
aided by powerful microscopes and marvellously delicate scales. But we
will stop only to note the powerful machine which is stretching and
crushing metal to ascertain its toughness. No care in experimenting is
spared. The chemist, poring over his test tubes, plays as important a
part in the construction of a car as the foundry man or the turner.

The machine-shop is an object-lesson among the tools noticed in
previous chapters of this book. "Here is a huge planing machine
travelling to and fro over a copper bar. A crank shaft has been cut out
of solid steel by boring holes close together through a thick plate,
and the two sides of the plate have been broken off, leaving the rough
shaft with its edges composed of a considerable number of semicircles.
The shaft is slowly rotated on a lathe, and tiny clouds of smoke arise
as the tool nicks off pieces of metal to reduce the shaft to a circular
shape. Other machines, with high-speed tool steel, are finishing gear
shafts. Fly-wheels are being turned and worm shafts cut. All these
laborious operations are carried out by the machines, each under the
control of one man whose mind is intent upon the work, ready to stop
the machine or adjust the material as may be required. As a contrast
to the heavy machines we will pass to the light automatic tools which
are grouped in a gallery.... The eye is bewildered by the moving mass,
but the whirling of the pulley shafts and the clicking of the capstan
lathes is soothing to the ear, while the mind is greatly impressed
by the ingenuity of man in suppressing labour by means of machines,
of which half a dozen can be easily looked after by one hand, who
has nothing to do but to see that they are fed with material. A rod
of steel is put into the machine, and the turret, with half a dozen
different tools, presents first one and then the other to the end of
the rod bathed in thick oil, so that it is rapidly turned, bored,
and shaped into caps, nuts, bolts, and the scores of other little
accessories required in fitting up a motor-car. On seeing how all this
work is done mechanically and methodically, with scarcely any other
expense but the capital required in the upkeep of the machines and in
driving them, one wonders how the automobile industry could be carried
on without this labour-saving mechanism. In any event, if all these
little pieces had to be turned out by hand, it is certain that the
cost of the motor-car would be considerably more than it is, even if
it did not reach to such a figure as to make it prohibitive to all but
wealthy buyers. Down one side of the gallery the machines are engaged
in cutting gears with so much precision that, when tested by turning
them together on pins on a bench at the end of the gallery, it is very
rare indeed that any one of them is found defective. This installation
of automatic tools is one of the largest of its kind in a motor-car
works, if not in any engineering shop, and each one has been carefully
selected in view of its efficiency for particular classes of work, so
that we see machines from America, England, France, and Germany."

In the fitting-shops the multitude of parts are assembled to form the
_chassis_ or mechanical carriage of the car, to which, in a separate
shop, is added the body for the accommodation of passengers. The whole
is painted and carefully varnished after it has been out on the road
for trials to discover any weak spot in its anatomy. Then the car is
ready for sale.

When one considers the racketing that a high-powered car has to stand,
and the high speed of its moving parts, one can understand why those
parts must be made so carefully and precisely, and also how this care
must conduce to the expense of the finished article. It has been said
that it is easy to make a good watch, but difficult to make a good
motor; for though they both require an equal amount of exactitude and
skill, the latter has to stand much more wear in proportion. When you
look at a first-grade car bearing a great maker's name, you have under
your eyes one of the most wonderful pieces of mechanism the world can
show.

We will not leave the de Dion-Bouton Works without a further glance
at the human element. The company never have a slack time, and
consequently can employ the same number of people all the year round.
They pride themselves on the fact that the great majority of the men
have been in their employ for several years, with the result that they
have around them a class of workmen who are steady, reliable and, above
all, skilful in the particular work they are engaged upon. There are
more than 2,600 men and about 100 women, these latter being employed
chiefly in the manufacture of sparking plugs and in other departments
where there is no night work. They are mostly the wives or widows of
old workmen, and in thus finding employment for them the firm provides
for those who would otherwise be left without resource, and at the same
time earns the gratitude of their employés.

NOTE.--The author gratefully acknowledges the help given by Messrs. de
Dion-Bouton, Ltd., in providing materials for this account of their
works.

THE MOTOR OMNIBUS

Prior to the emancipation of the road automobile in 1896, permission
had been granted to corporations to run trams driven by mechanical
power through towns. The steam tram, its engine protected by a case
which hid the machinery from the view of restive horses, panted up
and down our streets, drawing one or more vehicles behind it. The
electric tram presently came over from America and soon established
its superiority to the steamer with respect to speed, freedom from
smell and smoke, and noiselessness: the system generally adopted
was that invented in 1887 by Frank J. Sprague, in which an overhead
cable supported on posts or slung from wires spanning the track
carries current to a trolley arm projecting from the vehicle. The
return current passes through the rails, which are made electrically
continuous by having their individual lengths either welded together or
joined by metal strips.

In America, where wide streets and rapidly growing cities are the rule,
the electric tramway serves very useful ends; the best proof of its
utility being the total mileage of the tracks. Statistics for 1902
show that since 1890 the mileage had increased from 1,261 to 21,920
miles; and the number of passengers carried from 2,023,010,202 to
4,813,466,001, or an increase of 137·94 per cent. It is interesting to
note that electricity has in the United States almost completely ousted
steam and animal traction so far as street cars are concerned; since
the 5,661 miles once served by animal power have dwindled to 259, and
steam can claim only 169 miles of track.

Next to the United States comes Germany as a user of electricity
for tractive purposes; though she is a very bad second with only
about 6,000 miles of track; and England takes third place with about
3,000 miles. That the British Isles, so well provided with railways,
should be so poorly equipped with tramways is comprehensible when we
consider the narrowness of the streets of her largest towns, where
a good service of public vehicles is most needed. The installation
of a tram-line necessitates the tearing up of a street, and in many
cases the closing of that street to traffic. We can hardly imagine the
dislocation of business that would result from such a blockage of, say,
the Strand and High Holborn; but since it has been calculated that
no less than five millions of pounds sterling are lost to our great
metropolis yearly by the obstructions of gas, water, telegraph, and
telephone operations, which only partially close a thoroughfare, or by
the relaying of the road surface, which is not a very lengthy matter if
properly conducted, we might reckon the financial loss resulting from
the laying of tram-rails at many millions.

Even were they laid, the trouble would not cease, for a tram is
confined to its track, and cannot make way for other traffic. This
inadaptability has been the cause of the great outcry lately raised
against the way in which tram-line companies have monopolised the main
streets and approaches to many of our largest towns. While the electric
tram is beneficial to a large class of people, as a cheap method of
locomotion between home and business, it sadly handicaps all owners
of vehicles vexatiously delayed by the tram. At Brentford, to take a
notorious example, the double tram-line so completely fills the High
Street that it is at places impossible for a cart or carriage to remain
at the kerbstone.

Another charge levelled with justice at the tram-line is that the rails
and their setting are dangerous to cyclists, motorists, and even heavy
vehicles, especially in wet weather, when the "side-slip" demon becomes
a real terror.

English municipalities are therefore faced by a serious problem.
Improved locomotion is necessary; how can it best be provided? By
smooth-running, luxurious, well-lighted electric trams, travelling
over a track laid at great expense, and a continual nuisance to a
large section of the community; or by vehicles independent of a
central source of power, and free to move in any direction according
to the needs of the traffic? Where tramways exist, those responsible
for laying them at the rate of several thousand pounds per mile are
naturally reluctant to abandon them. But where the fixed track has
not yet arrived an alternative method of transport is open, viz. the
automobile omnibus. Quite recently we have seen in London and other
towns a great increase in the number of motor buses, which often
ply far out into the country. From the point of speed they are very
superior to the horsed vehicle, and statistics show that they are also
less costly to run in proportion to the fares carried, while passengers
will unanimously acknowledge their greater comfort. To change from
the ancient, rattling two-horse conveyance, which jolts us on rough
roads, and occasionally sends a thrill up the spine when the brakes are
applied, to the roomy steam- or petrol-driven bus, which overtakes and
threads its way through the slower traffic, is a pleasant experience.
So the motor buses are crowded, while the horsed rivals on the same
route trundle along half empty. Since the one class of vehicles can
travel at an average pace of ten miles an hour, as against the four
miles an hour of the other, no wonder that this should be so. Even if
the running costs of a motor bus for a given distance exceed that of
an electric tram, we must remember that, whereas a bus runs on already
existing roads, an immense amount of capital must be sunk in laying the
track for the tram, and the interest on this sum has to be added to the
total running costs.

The next decade will probably decide whether automobiles or trams are
to serve the needs of the community in districts where at present no
efficient service of any kind exists. In London motor buses are being
placed on the roads by scores, and the day cannot be far distant when
the horse will disappear from the bus as it is already fast vanishing
from the front of the tram.

Both petrol and steam, and in some cases a combination of petrol and
electricity, are used to propel the motor bus. It has not yet been
decided which form of power yields the best results. Petrol is probably
the cheaper fuel, but steam gives the quieter running; and could
electric storage batteries be made sufficiently light and durable they
would have a strong claim to precedence. There has lately appeared a
new form of accumulator--the von Rothmund--which promises well, since
weight for weight it far exceeds in capacity any other type, and is so
constructed that it will stand a lot of rough usage. A car fitted with
a von Rothmund battery scaling about 1,500 lbs. has run 200 miles on
one charge, and it is anticipated that with improvements in motors a
1,100-lb. battery will readily be run 150 miles as against the 50 miles
in the case of a lead battery of equal weight.

There is a large sphere open to the motor bus outside districts where
the electric tram would enter into serious competition with it. We
have before us a sketch-map of the Great Western Railway, one of the
most enterprising systems with regard to its use of motors to feed its
rails. No less than thirty road services are in operation, and their
number is being steadily augmented. In fact, it looks as if in the near
future the motor service will largely supplant the branch railway,
blessed with very few trains a day. A motor bus service plying every
half-hour between a town and the nearest important main-line station
would be more valuable to the inhabitants than half a dozen trains a
day, especially if the passenger vehicles were supplemented by lorries
for the carriage of luggage and heavy goods.

In this connection we may notice an invention of M. Renard--a motor
train of several vehicles towed by a single engine. We have all seen
the traction-engine puffing along with its tail of trucks, and been
impressed by the weight of the locomotive, and also by the manner in
which the train occupies a road when passing a corner. The weight is
necessary to give sufficient grip to move the whole train, while the
spreading of the vehicles across the thoroughfare on a curve arises
from the fact that each vehicle does not follow the path of that
preceding it, but describes part of a smaller circle.

M. Renard has, in his motor train, evaded the need for a heavy tractor
by providing _every_ vehicle with a pair of driving wheels, and
transmitting the power to those wheels by a special flexible propeller
shaft which passes from the powerful motor on the leading vehicle under
all the other vehicles, engaging in succession with mechanism attached
to all the driving axles. In this manner each car yields its quotum of
adhesion for its own propulsion, and the necessity for great weight is
obviated. Special couplings ensure that the path taken by the tractor
shall be faithfully followed by all its followers. A motor train of
this description has travelled from Paris to Berlin and drawn to itself
a great deal of attention.

"Will it," asks a writer in _The World's Work_, "ultimately displace
the conventional traction-engine and its heavy trailing waggons? Every
municipality and County Council is only too painfully cognisant of the
dire effects upon the roads exercised by the cumbrous wheels of these
unwieldy locomotives and trains. With the Renard train, however, the
trailing coaches can be of light construction, carried on ordinary
wheels which do not cut up or otherwise damage the roadway surface.
Many other advantages inherent in such a train might be enumerated.
The most important, however, are the flexibility of the whole train;
its complete control; faster speed without any attendant danger; its
remarkable braking arrangements as afforded by the continuous propeller
shaft gearing directly with the driving-wheels of each carriage; its
low cost of maintenance, serviceability, and instant use; and the
reduction in the number of men requisite for the attention of the train
while on a journey."

Were the system a success, it would find plenty of scope to convey
passengers and commodities through districts too sparsely populated
to render a railway profitable. People would talk about travelling or
sending goods by the "ten-thirty motor train," just as now we speak of
the "eleven-fifteen to town."

As a carrier and distributer of mails, the motor van has already
established a position. To quote but a couple of instances, there are
the services between London and Brighton, and Liverpool and Manchester.
In the Isle of Wight motor omnibuses connect all the principal towns
and villages. Each bus is a travelling post-office in which, by an
arrangement with the Postmaster-General, anybody may post letters at
the recognised stopping-places or whenever the vehicle has halted for
any purpose.

In Paris, London, Berlin, the motor mail van is a common sight. It has
even penetrated the interior of India, where the Maharajah of Gwalior
uses a specially fitted steam car for the delivery of his private
mails. And, as though to show that man alone shall not profit by the
new mode of locomotion, Paris owns a motor-car which conveys lost dogs
from the different police-stations to the Dogs' Home! In fact, there
seems to be no purpose to which a horse-drawn vehicle can be put, which
either has not been, or shortly will be, invaded by the motor.

RAILWAY MOTOR-CARS

In the early days of railway construction vehicles were used which
combined a steam locomotive with an ordinary passenger carriage. After
being abandoned for many years, the "steam carriage" was revived, in
1902, by the London and South Western and Great Western railways for
local service and the handling of passenger traffic on branch lines.
Since that year rail motor-cars have multiplied; some being run by
steam, others by petrol engines, and others, again, by electricity
generated by petrol engines. The first class we need not describe in
any detail, as it presents no features of peculiar interest.

The North Eastern has had in use two rail-motors, each fifty-two feet
long, with a compartment at each end for the driver, and a central
saloon to carry fifty-two passengers. An 80 h.p. four-cylindered
Wolseley petrol motor drives a Westinghouse electric generator, which
sends current into a couple of 55 h.p. electric motors geared to the
running-wheels. An air compressor fitted to the rear bogie supplies the
Westinghouse air brakes, while in addition a powerful electric brake
is fitted, acting on the rails as well as the wheels. The coach scales
thirty-five tons.

The chief advantage of this "composite" system of power transmission is
that the engine is kept running at a constant speed, while the power
it develops at the electric motors is regulated by switches which
control the action of the armature and field magnets. When heavy work
must be done the engine is supplied with more gaseous mixture, and the
generators are so operated as to develop full power. In this manner all
the variable speed gears and clutches necessary when the petrol motor
is connected to the driving-wheels are done away with.

The latter system gives, however, greater economy of fuel, and
the Great Northern Railway has adopted it in preference to the
petrol-electric. This railway has many small branch lines running
through thinly populated districts, which, though important as feeders
of the main tracks, are often worked at a loss. A satisfactory type of
automobile carriage would not only avoid this loss, but also largely
prevent the competition of road motors.

The car should be powerful enough to draw an extra van or two on
occasion, since horses and heavy luggage may sometimes accompany the
passengers. Messrs. Dick, Kerr, and Company have built a car, which,
when loaded with its complement of passengers, weighs about sixteen
tons. The motive power is supplied by two four-cylinder petrol engines
of the Daimler type, each giving 36 h.p. These are suspended on a
special frame, independent of that which carries the coach body, so
that the passengers are not troubled by the vibration of the engines,
even when the vehicle is at rest. The great feature of the car is the
lightness of the machinery--only two tons in weight--though it develops
sufficient power to move the carriage at fifty miles per hour. After
travelling 2,000 miles the machinery showed no appreciable signs of
wear; so that the company considers that it has found a reliable
type of motor for the working of the short line between Hatfield and
Hertford.

Since one man can drive a petrol car, while two--a driver and a
stoker--are necessary on a steam car, a considerable reduction in wages
will result from the employment of these vehicles.

Engineers find motor-trolleys very convenient for inspecting the lines
under their care. On the London and South Western Railway a trolley
driven by a 6-8 h.p. engine, and provided with a change-gear
giving six, fifteen, and thirty miles per hour in either direction,
is at work. It seats four persons. In the colonies, notably in
South Africa, where coal and wood fuel is scarce or expensive, the
motor-trolley, capable of carrying petrol for 300 miles' travel, is
rapidly gaining ground among railway inspectors.

Makers are turning their attention to petrol shunting engines, useful
in goods yards, mines, sewerage works. Firms such as Messrs. Maudslay
and Company, of Coventry; the Wolseley Tool and Motor Car Company;
Messrs. Panhard and Levassor; Messrs. Kerr, Stuart, and Company have
brought out locomotives of this kind which will draw loads up to sixty
tons. The fact that a petrol engine is ready for work at a moment's
notice, and when idle is not "eating its head off," and has no furnace
or boiler to require attention, is very much in its favour where
comparatively light loads have to be hauled.

CHAPTER VIII

THE MOTOR AFLOAT

PLEASURE BOATS--MOTOR LIFEBOATS--MOTOR FISHING BOATS--A MOTOR FIRE
FLOAT--THE MECHANISM OF THE MOTOR BOAT--THE TWO-STROKE MOTOR--MOTOR
BOATS FOR THE NAVY

Having made such conquests on land, and rendered possible aerial feats
which could scarcely have been performed by steam, the explosion motor
further vindicates its versatility by its fine exploits in the water.

At the Paris Exhibition of 1889 Gottlieb Daimler, the inventor who made
the petrol engine commercially valuable as an aid to locomotion, showed
a small gas-driven boat, which by most visitors to the Exhibition was
mistaken for an ordinary steam launch, and attracted little interest.
Not deterred by this want of appreciation, Mr. Daimler continued
to perfect the idea for which, with a prophet's eye, he saw great
possibilities; and soon motor launches became a fairly common sight
on German rivers. They were received with some enthusiasm in the
United States, as being particularly suitable for the inland lakes and
waterways with which that country is so abundantly blessed; but met
with small recognition from the English, who might reasonably have been
expected to take great interest in any new nautical invention. Now,
however, English manufacturers have awaked fully to their error; and
on all sides we see boats built by firms competing for the lead in an
industry which in a few years' time may reach colossal proportions.

[Illustration: A MODERN CAR AND BOAT

In the background is the racing motor boat "Napier II.", which on a
trial trip travelled over the "measured mile" at 30·93 miles per hour.
In the foreground is a "Napier" racing car, which has attained a speed
of 104·8 miles per hour.]

Until quite recently the marine motor was a small affair, developing
only a few horse-power. But because the gas-engine for automobile work
had been so vastly improved in the last decade, it attracted notice
as a rival to steam for driving launches and pleasure boats, and soon
asserted itself as a reliable mover of vessels of considerable size. To
promote the development of the industry, to test the endurance of the
machine, and to show the weak spots of mechanical design, trials and
races were organised on much the same lines as those which have kept
the motor-car so prominently before the public--races in the Solent,
across the Channel, and across the Mediterranean. The speed, as in the
case of cars, has risen very rapidly with the motor boat. When, in
February, 1905, a Napier racer did some trial spins over the measured
mile in the Thames at Long Reach, she attained 28·57 miles per hour on
the first run. On turning, the tide was favourable, and the figures
rose to 30·93 m.p.h., while the third improved on this by over a mile.
Her mean speed was 29·925 m.p.h., or about 2/3 m.p.h. better than the
previous record--standing to the credit of the American _Challenger_.
The latter had, however, the still waters of a lake for her venue, so
that the Napier's performance was actually even more creditable than
the mere figures would seem to imply. At a luncheon which concluded
the trial, Mr. Yarrow, who had built the steel hull, said: "To give an
idea of what an advance the adoption of the internal combustion engine
really represents, I should like to state that, if we were asked to
guarantee the best speed we could with a boat of the size of Napier
II., fitted with the latest form of steam machinery of as reliable a
character as the internal combustion engine in the present boat, we
should not like to name more than sixteen knots. So that it may be
taken that the adoption of the internal combustion engine, in place
of the steam-engine, for a vessel of this size, really represents an
additional speed of ten knots an hour. I should here point out that the
speed of a vessel increases rapidly with its size. For example: in what
is termed a second-class torpedo boat, sixty feet in length, the best
speed we could obtain would be twenty knots; but for a vessel of, say,
200 feet in length, with similar but proportionately larger machinery,
a speed of thirty knots could be obtained. Therefore, the obtaining of
a speed of practically twenty-six knots in the Yarrow-Napier boat, only
forty feet in length, points to the possibility, in the not far-distant
future, of propelling a vessel 220 feet in length at even forty-five
knots per hour. All that remains to be done is to perfect the internal
combustion engine, so as to enable large sizes to be successfully made."

Boats of 300 h.p. and upwards are being built; and the project has
been mooted of holding a transatlantic race, open to motor boats of
all sizes, which should be quite self-contained and able to carry
sufficient fuel to make the passage without taking in fresh supplies.
In view of the perils that would be risked by all but large craft, and
in consideration of the prejudice that motor boats might incur in event
of any fatalities, the Automobile Club of France set its face against
the venture, and it fell through. It is possible, however, that the
scheme may be revived as soon as larger motor boats are afloat, since
the Atlantic has actually been crossed by a craft of 12 h.p., measuring
only forty feet at the water-line. This happened in 1902, when Captain
Newman and his son, a boy twelve years old, started from New York, and
made Falmouth Harbour after thirty days of anxious travel over the
uncertain and sometimes tempestuous ocean. The boat, named the _Abiel
Abbot Low_, carried auxiliary sails of small size, and was not by any
means built for such a voyage. The engine--a two-cylinder--burned
kerosene. Captain Newman received £1,000 from the New York Kerosene
Oil Engine Company for his feat. The money was well earned. Though
provided with proper navigating instruments--which he knew how to
use well--Newman had a hard time of it to keep his craft afloat, his
watches sometimes lasting two days on end when the weather was bad. Yet
the brave pair won through; and probably even more welcome than the
sense of success achieved and the reward gained was the long two-days'
sleep which they were able to get on reaching Falmouth Harbour.

PLEASURE BOATS

We may now consider the pleasure and commercial uses of the motor boat
and marine motor. As a means of recreation a small dinghy driven by a
low-powered engine offers great possibilities. Its cost is low, its
upkeep small, and its handiness very great. Already a number of such
craft are furrowing the surface of the Thames, Seine, Rhine, and
many other rivers in Europe and America. While racing craft are for
the wealthy alone, many individuals of the class known as "the man of
moderate means" do not mind putting down £70 to £100 for a neat boat,
the maintenance of which is not nearly so serious a matter as that of a
small car. Tyre troubles have no counterpart afloat. The marine motor
dispenses with change gears. Water being a much more yielding medium
than Mother Earth, the shocks of starting and stopping are not such
as to strain machinery. Then again, the cooling of the cylinders is
a simple matter with an unlimited amount of water almost washing the
engine. And as the surface of water does not run uphill, a small motor
will show to better advantage on a river than on a road. Thus, a 5 h.p.
car will not conveniently carry more than two people if it is expected
to climb slopes at more than a crawl. Affix a motor of equal power to
a boat which accommodates half a dozen persons, and it will move them
all along at a smart pace as compared with the rate of travel given by
oars. After all, on a river one does not want to travel fast--rather to
avoid the hard labour which rowing undoubtedly does become with a craft
roomy enough to be comfortable for a party.

The marine motor also scores under the heading of adaptability. A
wagonette could not be converted into a motor-car with any success. But
a good-sized row-boat may easily blossom out as a useful self-propelled
boat. You may buy complete apparatus--motor, tanks, screw, batteries,
etc.--for clamping direct on to the stern, and there you are--a
motor boat while you wait! Even more sudden still is the conversion
effected by the Motogodille, which may be described as a motor screw
and rudder in one. The makers are the Buchet Company, a well-known
French firm. "Engine and carburetter, petrol tank, coil, accumulator,
lubricating oil reservoir, exhaust box, propeller shaft, and propeller
with guard are all provided, so that the outfit requires no additional
accessories. For mounting in position at the stern of the boat, the
complete set is balanced on a standard, and carries a steering arm,
on which the tanks are mounted; and also the stern tube and propeller
guard, which are in one solid piece, in addition to the engine. In
order that no balancing feats shall be required of the person in
charge, there is, on the supporting standard, a quadrant, in the
notches of which a lever on the engine frame engages, thus allowing the
rigid framework, and therefore the propeller shaft, to be maintained at
any angle to the vertical without trouble."[12]

The 2 h.p. engine drives a boat 16 feet long by 4 feet 6 inches beam
at 6-1/2 miles per hour through still water. As the Motogodille can be
swerved to right or left on its standard, it acts as a very efficient
rudder, while its action takes no way off the boat.

For people who like an easy life on hot summer days, reclining on
soft cushions, and peeping up through the branches which overhang
picturesque streams, there is the motor punt, which can move in
water so shallow that it would strand even a row-boat. The Oxford
undergraduate of to-morrow will explore the leafy recesses of the
"Cher," not with the long pole laboriously raised and pushed aft, but
by the power of a snug little motor throbbing gently at the stern.
And on the open river we shall see the steam launch replaced by craft
having much better accommodation for passengers, while free from the
dirt and smells which are inseparable from the use of steam-power. The
petrol launch will rival the electric in spaciousness, and the steamer
in its speed and power, size for size.

Some people have an antipathy to this new form of river locomotion on
account of the risks which accompany the presence of petrol. Were a
motor launch to ignite in, say, Boulter's Lock on a summer Sunday, or
at the Henley Regatta, there might indeed be a catastrophe. The same
danger has before now been flaunted in the face of the automobilist
on land; yet cases of the accidental ignition of cars are very, very
rare, and on the water would be more rare still, because the tanks
can be more easily examined for leaks. Still, it behoves every owner
of a launch to keep his eye very widely open for leakage, because any
escaping liquid would create a collection of gas in the bottom of the
boat, from which it could not escape like the gas forming from drops
spilled on the road.

_Photo Branger & Cie, Paris._

THE MOTOGODILLE

The Motogodille, or Motor Rudder, consists of a screw propeller fitted
to a small Buchet motor. The whole apparatus is mounted on a standard
in the stern, and the operator, by moving the inboard arm to right or
left, can steer the boat as he wishes. A 2-h.p. motor gives a speed of
5 to 6 miles an hour.]

The future popularity of the motor boat is assured. The waterside
dweller will find it invaluable as a means of carrying him to other
parts of the stream. The "longshoreman" will be able to venture much
further out to sea than he could while he depended on muscles or wind
alone, and with much greater certainty of returning up to time. A
whole network of waterways intersects civilised countries--often far
better kept than the roads--offering fresh fields for the tourist
to conquer. River scenery and beautiful scenery more often than not go
together. The car or cycle may be able to follow the course of a stream
from source to mouth; yet this is the exception rather than the rule.
We shoot _over_ the stream in the train or on our machines; note that
it looks picturesque; wonder vaguely whither it flows and whence it
comes; and continue our journey, recking little of the charming sights
to be seen by anyone who would trust himself to the water. Hitherto
the great difficulty has been one of locomotion. In a narrow stream
sailing is generally out of the question; haulage by man or beast
becomes tedious, even if possible; and rowing day after day presupposes
a good physical condition. In the motor boat the holiday maker has
an ideal craft. It occupies little room; can carry fuel sufficient
for long distances; is unwearying; and is economical as regards its
running expenses. We ought not to be surprised, therefore, if in a few
years the jaded business man turns as naturally to a spin or trip on
the rivers and canals of his country as he now turns to his car and
a rush over the dusty highway. Then will begin another era for the
disused canal, the vegetation-choked stream; and our maps will pay more
attention to the paths which Nature has water-worn in the course of the
ages.

To the scientific explorer also the motor affords valuable help. Many
countries, in which roads are practically non-existent, can boast fine
rivers fed by innumerable streams. What fields of adventure, sport, and
science would be open to the possessor of a fast launch on the Amazon,
the Congo, the Mackenzie, or the Orinoco, provided only that he could
occasionally replenish his fuel tanks!

MOTOR LIFEBOATS

Turning to the more serious side of life, we find the marine motor
still much in evidence. On account of its comparatively short existence
it is at present only in the experimental stage in many applications,
and time must pass before its position is fully established. Take,
for instance, the motor lifeboat lately built for the Royal National
Lifeboat Institution. Here are encountered difficulties of a kind very
different from those of a racing craft. A lifeboat is most valuable in
rough weather, which means more or less water often coming aboard. If
the water reached the machinery, troubles with the electrical ignition
apparatus would result. So the motor must be enclosed in a water-tight
compartment. And if so enclosed it must be specially reliable. Also,
since a lifeboat sometimes upsets, the machinery needs to be so
disposed as not to interfere with her self-righting qualities. The list
might easily be extended.

An account of the first motor life-saver will interest readers, so we
once again have recourse to the chief authority on such topics--the
_Motor Boat_--for particulars. The boat selected for experiment was an
old one formerly stationed at Folkestone, measuring thirty-eight feet
long by eight feet beam, pulling twelve oars, double-banked, and of
the usual self-righting type, rigged with jib, fore-lug, and mizzen.
After she had been hauled up in Mr. Guy's yard, where some of the
air-cases under the deck amidships were taken out, a strong mahogany
case, measuring four feet long by three feet wide and as high as the
gunwales, lined with sheet copper so as to be water-tight, with a
close-fitting lid which could be easily removed on shore, was fitted in
place, and the whole of the vital parts of the machinery, comprising
a two-cylinder motor of 10 h.p., together with all the necessary
pumps, carburetter, electric equipment, etc., were fitted inside this
case. The engine drives a three-bladed propeller through a long shaft
with a disconnecting clutch between, so that for starting or stopping
temporarily the screw can be disconnected from the engine. The petrol,
which serves as fuel for the engine, is carried in a metal tank stored
away inside the forward "end" box, where it is beyond any possibility
of accidental damage. Sufficient fuel for a continuous run of over ten
hours is carried. The engine is started by a handle fitted on the fore
side of the case, which can be worked by two men. The position and size
of the engine-case is such that only two oars are interfered with, but
it does not follow that the propelling power of the two displaced men
is entirely lost, because they can double bank some of the other oars
when necessary.

Fitted thus, the lifeboat was tested in all sorts of weather during
the month of April, and it was found that she could be driven fairly
well against a sea by means of the motor alone; but when it was used
to assist the sails the true use of the motor as an auxiliary became
apparent, and the boat would work to windward in a way previously
unattainable. Neither the pitching or rolling in a seaway, in any
weather then obtainable, interfered at all with the proper working or
starting of the motor, which worked steadily and well throughout.
Having been through these preliminary tests, she was more severely
tried. Running over the measured mile with full crew and stores on
board, she developed over six knots an hour. The men were then replaced
by equivalent weights lashed to the thwarts, and she was capsized
by a crane four times, her sails set and the sheets made fast, yet
she righted herself without difficulty. An interesting feature of
the capsize was that the motor stopped automatically when the boat
had partly turned over. This arrangement prevents her from running
away from the crew if they should be pitched out. The motor started
again after a few turns of the handle, so proving that the protecting
compartment had kept the water at bay.

From this account it is obvious that a valuable aid to life-saving
at sea has been found. The steam lifeboat, propelled by a jet of
water squirted out by pumps below the water line, is satisfactory so
long as the boat keeps upright. But in event of an upset the fires
must necessarily be extinguished. No such disability attends the
petrol-driven craft, and we shall be glad to think that the brave
fellows who risk their lives in the cause of humanity will be spared
the intense physical toil which a long row to windward in a heavy sea
entails. The general adoption of this new ally will take time, and must
depend largely on the liberality of subscribers to the fine institution
responsible for lifeboat maintenance; but it is satisfactory to learn
that the Committee has given the boat in question a practical chance in
the open sea by stationing her at Newhaven, Sussex, as a unit in the
lifeboat fleet.

MOTOR FISHING BOATS

It is a pretty sight to watch a fishing fleet enter the harbour with
its catch, taken far away on the waters beyond the horizon while
landsmen slept. The sails, some white, some brown, some wondrously
patched and bearing the visible marks of many a hard fight with the
wind, belly out in graceful lines as the boats slip past the harbour
entrance. No wonder that the painter has so often found subjects for
his canvas and brushes among the toilers of the deep.

But underlying the romance and picturesqueness of the craft there is
stern business. Those boats may be returning with full cargoes, such as
will yield good profits to owner and crew; or, on the other hand, the
hold may be empty, and many honest hearts be heavy at the thought of
wasted days. A few years ago the Yarmouth herring fleet is said to have
returned on one occasion with but a single fish to the credit of the
whole fleet! This might have been a mere figure of speech; it stands,
at any rate, for many thousands of pounds lost by the hardy fishermen.

When the boats have been made fast, the fish, if already disentangled
from the nets, is usually sold at once by auction, the price depending
largely on the individual size and freshness of the "catch." Now, with
the increase in the number of boats and from other causes, the waters
near home have been so well fished over that much longer journeys
must be made to the "grounds" than were formerly necessary. Trawling,
that is, dragging a large bag-net--its mouth kept open by a beam and
weights--along the bottom of the sea for flatfish, has long been
performed by powerful steam vessels, which may any day be seen leaving
or entering Hull or Grimsby in large numbers. Surface fishing, wherein
a long drift-net, weighted at its lower edge and buoyed at the upper
edge to enable it to keep a perpendicular position, is used for herring
and mackerel, and in this industry wind power alone is generally used
by British fishermen.

The herring-boat sets sail for the grounds in the morning, and at
sundown should be at the scene of action. Her nets, aggregating,
perhaps, a mile in length, are then "shot," and the boat drifts along
towing the line behind her. If fish appear, the nets are hauled in soon
after daybreak by the aid of a capstan. The labour of bringing a mile
of nets aboard is very severe--so severe, in fact, that the larger
boats in many cases employ the help of a small steam-engine. During the
return voyage the fish is freed from the meshes, and thrown into the
hold ready for sale as soon as land is reached.

Fish, whether for salting or immediate consumption, should be fresh.
No class of human food seems to deteriorate so quickly when life
is extinct as the "denizens of the deep," so that it is of primary
importance to fishermen that their homeward journey should be performed
in the shortest possible time. If winds are contrary or absent there
may be such delay as to need the liberal use of salt, and even that
useful commodity will not stave off a fall in value.

It therefore often happens that a really fine catch arrives at its
market in a condition which spells heavy loss to the catchers. A slow
return also means missing a day's fishing, which may represent £200 to
£300. For this reason the Dogger Bank fishing fleet is served by steam
tenders, which carry off the catches as they are made, and thus obviate
the necessity for a boat's return to port when its hold is full. Such a
system will not, however, be profitable to boats owned by individuals,
and working within a comparatively short distance of land.

Each boat must depend on its particular powers, the first to return
getting rather better prices than those which come "with the crowd." So
steam power is in some cases installed as an auxiliary to the sails,
though it may entail the outlay of £2,000 as first cost, and a big bill
for upkeep and management. "Small" men cannot afford this expense,
and they would be doomed to watch their richer brethren slip into the
market before them had not the explosion motor come to their aid.
This just meets their case; it is not nearly so expensive to install
as steam, occupies much less room, is easier to handle, and therefore
saves the expense of trained attendants.

Fishermen are notoriously conservative. To them a change from methods
sanctioned by many years of practice is abhorrent. What sufficed for
their fathers, they say, should suffice for them. Their trade is so
uncertain that a bad season would see no return for the cost of the
motor, since, where no fish are caught, it makes little difference
whether the journey to port be quick or slow.

However, the motor is bound to come. It has been applied to fishing
boats with marked success. While the nets are out, the motor is
stopped, and costs not a penny more till the time comes for hauling
in. Then it is geared up with a capstan, and saves the crew much of
their hardest work. When all is aboard, the capstan hands over the
power to the screw, which, together with the sails, propels the vessel
homewards at a smart pace. The skipper is certain of making land in
good time for the market; and he will be ready for the out voyage next
morning. Another point in favour of the motor is that, when storms
blow up, the fleet will be able to run for shelter even if the wind be
adverse; and we should hear less of the sacrifice of life which makes
sad reading after every severe gale.

As to the machinery to be employed, Mr. F. Miller, of Oulton
Broad, who first applied the gas-motor to a fishing smack--the
_Pioneer_--considers that a 12 h.p. engine would suffice as an
auxiliary for small craft of the class found in the northern parts
of Great Britain. The Norfolk boats would require a 30 h.p.; and
a full-powered boat--_i.e._ one that could depend on the motor
entirely--should carry a three-cylinder engine of 80 h.p. In any
case, the machinery must be enclosed and well protected; while the
lubrication arrangements should be such as to be understood easily by
unskilled persons, and absolutely reliable. Owing to the moisture in
the atmosphere the ordinary high-tension coil ignition, such as is used
on most motor-cars, would not prove efficient, and it is therefore
replaced by a low-tension type which makes and breaks the primary
circuit by means of a rocking arm working through the walls of the
cylinder. Lastly, all parts which require occasional examination or
adjustment must be easily accessible, so that they may receive proper
attention at sea, and not send the vessel home a "lame duck" under sail.

The advantages of the motor are so great that the Scotch authorities
have taken the matter up seriously, appointing an expert to make
inquiries. It is therefore quite possible that before many years have
elapsed the motor will play an important part in the task of supplying
our breakfast tables with the dainty sole or toothsome herring.

A MOTOR FIRE FLOAT

As a good instance of this particular adaptation of the explosion
engine to fire-extinction work, we may quote the apparatus now in
attendance on the huge factory of Messrs. Huntley and Palmer, the
famous Reading biscuit makers. The factory lies along the banks of the
river Kennet, which are joined by bridges so close to the water that
a steamer could not pass under them. Messrs. Merryweather accordingly
built the motor float, 32 feet long, 9-1/2 feet beam, and drawing
27 inches. Two engines, each having four cylinders of a total of 30
h.p., drive two sets of three-cylinder "Hatfield" pumps, which give a
continuous feed to the hose. Engines and pumps are mounted on a single
bed-plate, and are worked separately, unless it be found advisable to
"Siamese" the hoses to feed a single 1-1/2-inch jet, which can be flung
to a great height.

One of the most interesting features of the float is the method of
propulsion. As its movements are limited to a few hundred yards, the
fitting of a screw was considered unnecessary, its place being taken by
four jets, two at each end, through which water is forced against the
outside water by the extinguishing pumps. These will move the float
either forward or astern, steer her, or turn her round.

So here once again petrol has trodden upon the toes of Giant Steam: and
very effectively, too.

THE MECHANISM OF THE MOTOR BOAT

In many points the marine motor reproduces the machinery built into
cars. The valve arrangements, governors, design of cylinders and
water-jackets are practically the same. Small boats carry one cylinder
or perhaps two, just as a small car is content with the same number;
but a racing or heavy boat employs four, six, and, in one case at
least, twelve cylinders, which abolish all "dead points" and enable the
screw to work very slowly without engine vibration, as the drive is
continuous.