In 1807, the first practical steamboat puffed slowly up the Hudson,
while the people ranged along the banks gazed in wonder. Even the grim
walls of the Palisades must have been surprised at the strange intruder.
Robert Fulton's _Clermont_ was the forerunner of the fleets upon fleets
of power-driven craft that have stemmed the currents of a thousand
streams and parted the waves of many seas.
The _Clermont_ took several days to go from New York to Albany, and the
trip was the wonder of that time.
During the summer of 1902 a long, slim, white craft, with a single brass
smokestack and a low deck-house, went gliding up the Hudson with a kind
of crouching motion that suggested a cat ready to spring. On her deck
several men were standing behind the pilot-house with stop-watches in
their hands. The little craft seemed alive under their feet and quivered
with eagerness to be off. The passenger boats going in the same
direction were passed in a twinkling, and the tugs and sailing vessels
seemed to dwindle as houses and trees seem to shrink when viewed from
the rear platform of a fast train.
Two posts, painted white and in line with each other--one almost at the
river's edge, the other 150 feet back--marked the starting-line of a
measured mile, and were eagerly watched by the men aboard the yacht. She
sped toward the starting-line as a sprinter dashes for the tape; almost
instantly the two posts were in line, the men with watches cried "Time!"
and the race was on. Then began such a struggle with Father Time as was
never before seen; the wind roared in the ears of the passengers and
snatched their words away almost before their lips had formed them; the
water, a foam-flecked streak, dashed away from the gleaming white sides
as if in terror. As the wonderful craft sped on she seemed to settle
down to her work as a good horse finds himself and gets into his stride.
Faster and faster she went, while the speed of her going swept off the
black flume of smoke from her stack and trailed it behind, a dense,
low-lying shadow.
"Look!" shouted one of the men into another's ear, and raised his arm to
point. "We're beating the train!"
[Illustration: THE STEAM TURBINE-DRIVEN _VELOX_, OF THE BRITISH NAVY
The fastest torpedo-boat destroyer.]
Sure enough, a passenger train running along the river's edge, the
wheels spinning round, the locomotive throwing out clouds of smoke, was
dropping behind. The train was being beaten by the boat. Quivering,
throbbing with the tremendous effort, she dashed on, the water climbing
her sides and lashing to spume at her stern.
"Time!" shouted several together, as the second pair of posts came in
line, marking the finish of the mile. The word was passed to the
frantically struggling firemen and engineers below, while those on deck
compared watches.
"One minute and thirty-two seconds," said one.
"Right," answered the others.
Then, as the wonderful yacht _Arrow_ gradually slowed down, they tried
to realise the speed and to accustom themselves to the fact that they
had made the fastest mile on record on water.
And so the _Arrow_, moving at the rate of forty-six miles an hour,
followed the course of her ancestress, the _Clermont_, when she made her
first long trip almost a hundred years before.
The _Clermont_ was the first practical steamboat, and the _Arrow_ the
fastest, and so both were record-breakers. While there are not many
points of resemblance between the first and the fastest boat, one is
clearly the outgrowth of the other, but so vastly improved is the modern
craft that it is hard to even trace its ancestry. The little _Arrow_ is
a screw-driven vessel, and her reciprocating engines--that is, engines
operated by the pulling and pushing power of the steam-driven pistons in
cylinders--developed the power of 4,000 horses, equal to 32,000 men,
when making her record-breaking run. All this enormous power was used to
produce speed, there being practically no room left in the little
130-foot hull for anything but engines and boilers.
There is little difference, except in detail, between the _Arrow's_
machinery and an ordinary propeller tugboat. Her hull is very light for
its strength, and it was so built as to slip easily through the water.
She has twin engines, each operating its own shaft and propeller. These
are quadruple expansion. The steam, instead of being allowed to escape
after doing its work in the first cylinder, is turned into a larger one
and then successively into two more, so that all of its expansive power
is used. After passing through the four cylinders, the steam is
condensed into water again by turning it into pipes around which
circulates the cool water in which the vessel floats. The steam thus
condensed to water is heated and pumped into the boiler, to be turned
into steam, so the water has to do its work many times. All this saves
weight and, therefore, power, for the lighter a vessel is the more
easily she can be driven. The boilers save weight also by producing
steam at the enormous pressure of 400 pounds to the square inch.
Steadily maintained pressure means power; the greater the pressure the
more the power. It was the inventive skill of Charles D. Mosher, who has
built many fast yachts, that enabled him to build engines and boilers of
great power in proportion to their weight. It was the ability of the
inventor to build boilers and engines of 4,000 horse-power compact and
light enough to be carried in a vessel 130 feet long, of 12 feet 6
inches breadth, and 3 feet 6 inches depth, that made it possible for the
_Arrow_ to go a mile in one minute and thirty-two seconds. The speed of
the wonderful little American boat, however, was not the result of any
new invention, but was due to the perfection of old methods.
In England, about five years before the _Arrow's_ achievement, a little
torpedo-boat, scarcely bigger than a launch, set the whole world talking
by travelling at the rate of thirty-nine and three-fourths miles an
hour. The little craft seemed to disappear in the white smother of her
wake, and those who watched the speed trial marvelled at the railroad
speed she made. The _Turbina_--for that was the little record-breaker's
name--was propelled by a new kind of engine, and her speed was all the
more remarkable on that account. C.A. Parsons, the inventor of the
engine, worked out the idea that inventors have been studying for a long
time--since 1629, in fact--that is, the rotary principle, or the rolling
movement without the up-and-down driving mechanism of the piston.
The _Turbina_ was driven by a number of steam-turbines that worked a
good deal like the water-turbines that use the power of Niagara. Just as
a water-wheel is driven by the weight or force of the water striking the
blades or paddles of the wheel, so the force of the many jets of steam
striking against the little wings makes the wheels of the steam-turbines
revolve. If you take a card that has been cut to a circular shape and
cut the edges so that little wings will be made, then blow on this
winged edge, the card will revolve with a buzz; the Parsons
steam-turbine works in the same way. A shaft bearing a number of steel
disks or wheels, each having many wings set at an angle like the blades
of a propeller, is enclosed by a drumlike casing. The disks at one end
of the shaft are smaller than those at the other; the steam enters at
the small end in a circle of jets that blow against the wings and set
them and the whole shaft whirling. After passing the first disk and its
little vanes, the steam goes through the holes of an intervening fixed
partition that deflects it so that it blows afresh on the second, and so
on to the third and fourth, blowing upon a succession of wheels, each
set larger than the preceding one. Each of Parsons's steam-turbine
engines is a series of turbines put in a steel casing, so that they use
every ounce of the expansive power of the steam.
It will be noticed that the little wind-turbine that you blow with your
breath spins very rapidly; so, too, do the wheels spun by the steamy
breath of the boilers, and Mr. Parsons found that the propeller fastened
to the shaft of his engine revolved so fast that a vacuum was formed
around the blades, and its work was not half done. So he lengthened his
shaft and put three propellers on it, reducing the speed, and allowing
all of the blades to catch the water strongly.
The _Turbina_, speeding like an express train, glided like a ghost over
the water; the smoke poured from her stack and the cleft wave foamed at
her prow, but there was little else to remind her inventor that 2,300
horse-power was being expended to drive her. There was no jar, no shock,
no thumping of cylinders and pounding of rapidly revolving cranks; the
motion of the engine was rotary, and the propeller shafts, spinning at
2,000 revolutions per minute, made no more vibration than a windmill
whirling in the breeze.
To stop the _Turbina_ was an easy matter; Mr. Parsons had only to turn
off the steam. But to make the vessel go backward another set of
turbines was necessary, built to run the other way, and working on the
same shaft. To reverse the direction, the steam was shut off the engines
which revolved from right to left and turned on those designed to run
backward, or from left to right. One set of the turbines revolved the
propellers so that they pushed, and the other set, turning them the
other way, pulled the vessel backward--one set revolving in a vacuum and
doing no work, while the other supplied the power.
The Parsons turbine-engines have been used to propel torpedo-boats, fast
yachts, and vessels built to carry passengers across the English
Channel, and recently it has been reported that two new transatlantic
Cunarders are to be equipped with them.
[Illustration: THE ENGINES OF THE _ARROW_]
A few years after the Pilgrims sailed for the land of freedom in the
tiny _Mayflower_ a man named Branca built a steam-turbine that worked in
a crude way on the same principle as Parsons's modern giant. The
pictures of this first steam-turbine show the head and shoulders of a
bronze man set over the flaming brands of a wood fire; his metallic
lungs are evidently filled with water, for a jet of steam spurts from
his mouth and blows against the paddles of a horizontal turbine wheel,
which, revolving, sets in motion some crude machinery.
There is nothing picturesque about the steel-tube lungs of the boilers
used by Parsons in the _Turbina_ and the later boats built by him, and
plain steel or copper pipes convey the steam to the whirling blades of
the enclosed turbine wheels, but enormous power has been generated and
marvellous speed gained. In the modern turbine a glowing coal fire, kept
intensely hot by an artificial draft, has taken the place of the blazing
sticks; the coils of steel tubes carrying the boiling water surrounded
by flame replace the bronze-figure boiler, and the whirling, tightly
jacketed turbine wheels, that use every ounce of pressure and save all
the steam, to be condensed to water and used over again, have grown out
of the crude machine invented by Branca.
As the engines of the _Arrow_ are but perfected copies of the engine
that drove the _Clermont_, so the power of the _Turbina_ is derived from
steam-motors that work on the same principle as the engine built by
Branca in 1629, and his steam-turbine following the same old, old, ages
old idea of the moss-covered, splashing, tireless water-wheel.