Suppose some one should discover a new mechanical principle--something
as fundamental as James Watt's discovery of the expansive power
of steam--by the use of which it became possible to build a motor
that would give ten horse power for every pound of the engine's
weight, a motor so simple that the veriest novice in mechanics
could construct it and so elemental that it could not possibly
get out of repair. Then suppose that this motor could be run
forward or backward at will, that it could be used as either
an engine or a pump, that it cost almost nothing to build as
compared with any other known form of engine, that it utilized
a larger percentage of the available power than any existing
machine, and, finally, that it would operate with gas, steam,
compressed air or water, any one of them, as its driving power.
It does not take a mechanical expert to imagine the limitless
possibilities of such an engine. It takes very little effort
to conjure up a picture of a new world of industry and transportation
made possible by the invention of such a device. "Revolutionary"
seems a mild term to apply to it. That, however, is the word
the inventor uses in describing it--Nikola Tesla, the scientist
whose electrical discoveries underlie all modern electrical power
development, whose experiments and deductions made the wireless
telegraph possible, and who now, in the mechanical field, has
achieved a triumph even more far reaching than anything he accomplished
in electricity. There is something of the romantic in this discovery
of the famous explorer of the hidden realms of knowledge. The
pursuit of an ideal is always romantic, and it was in the pursuit
of an ideal which he has been seeking twenty years that Dr. Tesla
made his great discovery. That ideal is the power to fly--to
fly with certainty and absolute safety--not merely to go up in
an aeroplane and take chances on weather conditions, "holes
in the air," tornadoes, lightning and the thousand other
perils the aviator of today faces, but to fly with the speed
and certainty of a cannon ball, with power to overcome any of
nature's aerial forces, to start when one pleases, go whither
one pleases and alight where one pleases. That has been the aim
of Dr. Tesla's life for nearly a quarter of a century. He believes
that with the discovery of the principle of his new motor he
has solved this problem and that incidentally he has laid the
foundations for the most startling new achievements in other
mechanical lines.
There was a time when men of science were skeptical--a time when
they ridiculed the announcement of revolutionary discoveries.
Those were the days when Nikola Tesla, the young scientist from
the Balkans, was laughed at when he urged his theories on the
engineering world. Times have changed since then, and the "practical"
engineer is not so incredulous about "scientific" discoveries.
The change came about when young Tesla showed the way by which
the power of Niagara Falls could be utilized. The right to divert
a portion of the waters of Niagara had been granted; then arose
the question of how best to utilize the tremendous power thus
made available--how to transmit it to the points where it could
be commercially utilized. An international commission sat in
London and listened to theories and practical plans for months.
Up to that time the only means of utilizing electric power was
the direct current motor, and direct current dynamos big enough
to be of practical utility for such a gigantic power development
were not feasible. Then came the announcement of young Tesla's
discovery of the principle of the alternating current motor.
Practical tests showed that it could be built--that it would
work. That discovery, at that opportune time, decided the commission.
Electricity was determined upon as the means for the transmission
of Niagara's power to industry and commerce. Today a million
horse power is developed on the brink of the great cataract,
turning the wheels of Buffalo, Rochester, Syracuse and the intervening
cities and villages operating close at hand the great new electro-chemical
industries that the existence of this immense source of power
has made possible, while all around the world a thousand waterfalls
are working in the service of mankind, sending the power of their
"white coal" into remote and almost inaccessible corners
of the globe, all because of Nikola Tesla's first great epoch
making discovery. Today the engineering world listens respectfully
when Dr. Tesla speaks. The first announcement of the discovery
of his new mechanical principle was made in a technical periodical
in mid-September, 1911. Immediately it became the principal topic
of discussions wherever engineers met. "It is the greatest
invention in a century," wrote one of the foremost American
engineers, a man whose name stands close to the top of the list
of those who have achieved scientific fame and greatness. "No
invention of such importance in the automobile trade has yet
been made," declared the editor of one of the leading engineering
publications. Experts in other engineering lines pointed out
other applications of the new principle and letters asking for
further information poured in on Dr. Tesla from the four quarters
of the globe. "Oh, I've had too much publicity," he
said, when I telephoned to him to ask for an interview in order
to explain his new discovery to the non-technical public. It
took a good deal of persuasion before he reluctantly fixed an
hour when he would see me, and a good bit more after that before
he talked at all freely. When he did speak, however, he opened
up vistas of possible applications of the new engine that staggered
the imagination of the interviewer. Looking out over the city
from the windows of his office, on the twentieth floor of the
Metropolitan Tower, his face lit up as he told of his life dream
and its approaching realization, and the listener's fancy could
almost see the air full of strange flying craft, while huge steamships
propelled at unheard of speeds ploughed the waters of the North
River, automobiles climbed the very face of the Palisades, locomotives
of incredible power whisked wheeled palaces many miles a minute
and all the discomforts of summer heat vanished as marvelous
refrigerating plants reduced the temperature of the whole city
to a comfortable maximum--for these were only a few of the suggestions
of the limitless possibilities of the latest Tesla discovery.
"Just what is your new invention?" I asked. "I
have accomplished what mechanical engineers have been dreaming
about ever since the invention of steam power," replied
Dr. Tesla. "That is the perfect rotary engine. It happens
that I have also produced an engine which will give at least
twenty-five times as much power to a pound of weight as the lightest
weight engine of any kind that has yet been produced. "In
doing this I have made use of two properties which have always
been known to be possessed by all fluids, but which have not
heretofore been utilized. These properties are adhesion and viscosity.
"Put a drop of water on a metal plate. The drop will roll
off, but a certain amount of the water will remain on the plate
until it evaporates or is removed by some absorptive means. The
metal does not absorb any of the water, but the water adheres
to it. "The drop of water may change its shape, but until
its particles are separated by some external power it remains
intact. This tendency of all fluids to resist molecular separation
is viscosity. It is especially noticeable in the heavier oils.
"It is these properties of adhesion and viscosity that cause
the 'skin friction' that impedes a ship in its progress through
the water or an aeroplane in going through the air. All fluids
have these qualities--and you must keep in mind that air is a
fluid, all gases are fluids, steam is fluid. Every known means
of transmitting or developing mechanical power is through a fluid
medium. "Now, suppose we make this metal plate that I have
spoken of circular in shape and mount it at its centre on a shaft
so that it can be revolved. Apply power to rotate the shaft and
what happens? Why, whatever fluid the disk happens to be revolving
in is agitated and dragged along in the direction of rotation,
because the fluid tends to adhere to the disk and the viscosity
causes the motion given to the adhering particles of the fluid
to be transmitted to the whole mass. Here, I can show you better
than tell you. Dr. Tesla led the way into an adjoining room.
On a desk was a small electric motor and mounted on the shaft
were half a dozen flat disks, separated by perhaps a sixteenth
of an inch from one another, each disk being less than that in
thickness. He turned a switch and the motor began to buzz. A
wave of cool air was immediately felt. "There we have a
disk, or rather a series of disks, revolving in a fluid--the
air," said the inventor. "You need no proof to tell
you that the air is being agitated and propelled violently. If
you will hold your hand over the centre of these disks--you see
the centres have been cut away--you will feel the suction as
air is drawn in to be expelled from the peripheries of the disks.
"Now, suppose these revolving disks were enclosed in an
air tight case, so constructed that the air could enter only
at one point and be expelled only at another--what would we have?"
"You'd have an air pump," I suggested. "Exactly--an
air pump or blower," said Dr. Tesla. "There is one
now in operation delivering ten thousand cubic feet of air a
minute. "Now, come over here. He stepped across the hall
and into another room, where three or four draughtsmen were at
work and various mechanical and electrical contrivances were
scattered about. At one side of the room was what appeared to
be a zinc or aluminum tank, divided into two sections, one above
the other, while a pipe that ran along the wall above the upper
division of the tank was connected with a little aluminum case
about the size and shape of a small alarm clock. A tiny electric
motor was attached to a shaft that protruded from one side of
the aluminum case. The lower division of the tank was filled
with water. "Inside of this aluminum case are several disks
mounted on a shaft and immersed in a fluid, water," said
Dr. Tesla. "From this lower tank the water has free access
to the case enclosing the disks. This pipe leads from the periphery
of the case. I turn the current on, the motor turns the disks
and as I open this valve in the pipe the water flows. He turned
the valve and the water certainly did flow. Instantly a stream
that would have filled a barrel in a very few minutes began to
run out of the pipe into the upper part of the tank and thence
into the lower tank. "This is only a toy," said Dr.
Tesla. "There are only half a dozen disks--'runners,' I
call them--each less than three inches in diameter, inside of
that case. They are just like the disks you saw on the first
motor--no vanes, blades or attachments of any kind. Just perfectly
smooth, flat disks revolving in their own planes and pumping
water because of the viscosity and adhesion of the fluid. One
such pump now in operation, with eight disks, eighteen inches
in diameter, pumps four thousand gallons a minute to a height
of 360 feet. We went back into the big, well lighted office.
I was beginning to grasp the new Tesla principle. "Suppose
now we reversed the operation," continued the inventor.
"You have seen the disks acting as a pump. Suppose we had
water, or air under pressure, or steam under pressure, or gas
under pressure, and let it run into the case in which the disks
are contained--what would happen?" "The disks would
revolve and any machinery attached to the shaft would be operated--you
would convert the pump into an engine," I suggested. "That
is exactly what would happen--what does happen," replied
Dr. Tesla. "It is an engine that does all that engineers
have ever dreamed of an engine doing, and more. Down at the Waterside
power station of the New York Edison Company, through their courtesy,
I have had a number of such engines in operation. In one of them
the disks are only nine inches in diameter and the whole working
part is two inches thick. With steam as the propulsive fluid
it develops 110-horse power, and could do twice as much. "You
have got what Professor Langley was trying to evolve for his
flying machine--an engine that will give a horse power for a
pound of weight," I suggested. Ten Horse Power to the Pound.
"I have got more than that," replied Dr. Tesla. "I
have an engine that will give ten horse power to the pound of
weight. That is twenty-five times as powerful as the lightest
weight engine in use today. The lightest gas engine used on aeroplanes
weighs two and one-half pounds to the horse power. With two and
one-half pounds of weight I can develop twenty-five horse power.
"That means the solution of the problem of flying,"
I suggested. "Yes, and many more," was the reply. "The
applications of this principle, both for imparting power to fluids,
as in pumps, and for deriving power from fluids, as in turbine,
are boundless. It costs almost nothing to make, there is nothing
about it to get out of order, it is reversible--simply have two
ports for the gas or steam, to enter by, one on each side, and
let it into one side or other. There are no blades or vanes to
get out of order--the steam turbine is a delicate thing. I remembered
the bushels of broken blades that were gathered out of the turbine
casings of the first turbine equipped steamship to cross the
ocean, and realized the importance of this phase of the new engine.
"Then, too," Dr. Tesla went on, "there are no
delicate adjustments to be made. The distance between the disks
is not a matter of microscopic accuracy and there is no necessity
for minute clearances between the disks and the case. All one
needs is some disks mounted on a shaft, spaced a little distance
apart and cased so that a fluid can enter at one point and go
out at another. If the fluid enters at the centre and goes out
at the periphery it is a pump. If it enters at the periphery
and goes out at the center it is a motor. "Coupling these
engines in series, one can do away with gearing in machinery.
Factories can be equipped without shafting. The motor is especially
adapted to automobiles, for it will run on gas explosions as
well as on steam. The gas or steam can be let into a dozen ports
all around the rim of the case if desired. It is possible to
run it as a gas engine with a continuous flow of gas, gasoline
and air being mixed and the continuous combustion causing expansion
and pressure to operate the motor. The expansive power of steam,
as well as its propulsive power, can be utilized as in a turbine
or a reciprocating engine. By permitting the propelling fluid
to move along the lines of least resistance a considerably larger
proportion of the available power is utilized. "As an air
compressor it is highly efficient. There is a large engine of
this type now in practical operation as an air compressor and
giving remarkable service. Refrigeration on a scale hitherto
never attempted will be practical, through the use of this engine
in compressing air, and the manufacture of liquid air commercially
is now entirely feasible. "With a thousand horse power engine,
weighing only one hundred pounds, imagine the possibilities in
automobiles, locomotives and steamships. In the space now occupied
by the engines of the Lusitania twenty-five times her 80,000
horse power could be developed, were it possible to provide boiler
capacity sufficient to furnish the necessary steam. "And
it makes the aeroplane practical," I suggested. "Not
the aeroplane, the flying machine," responded Dr. Tesla.
"Now you have struck the point in which I am most deeply
interested--the object toward which I have been devoting my energies
for more than twenty years--the dream of my life. It was in seeking
the means of making the perfect flying machine that I developed
this engine. "Twenty years ago I believed that I would be
the first man to fly; that I was on the track of accomplishing
what no one else was anywhere near reaching. I was working entirely
in electricity then and did not realize that the gasoline engine
was approaching a perfection that was going to make the aeroplane
feasible. There is nothing new about the aeroplane but its engine,
you know. "What I was working on twenty years ago was the
wireless transmission of electric power. My idea was a flying
machine propelled by an electric motor, with power supplied from
stations on the earth. I have not accomplished this as yet, but
am confident that I will in time. "When I found that I had
been anticipated as to the flying machine, by men working in
a different field I began to study the problem from other angles,
to regard it as a mechanical rather than an electrical problem.
I felt certain there must be some means of obtaining power that
was better than any now in use, and by vigorous use of my gray
matter for a number of years I grasped the possibilities of the
principle of the viscosity and adhesion of fluids and conceived
the mechanism of my engine. Now that I have it, my next step
will be the perfect flying machine. "An aeroplane driven
by your engine?" I asked. "Not at all," said Dr.
Tesla. "The aeroplane is fatally defective. It is merely
a toy--a sporting play-thing. It can never become commercially
practical. It has fatal defects. One is the fact that when it
encounters a downward current of air it is helpless. The 'hole
in the air' of which aviators speak is simply a downward current,
and unless the aeroplane is high enough above the earth to move
laterally but can do nothing but fall. "There is no way
of detecting these downward currents, no way of avoiding them,
and therefore the aeroplane must always be subject to chance
and its operator to the risk of fatal accident. Sportsmen will
always take these chances, but as a business proposition the
risk is too great. "The flying machine of the future--my
flying machine--will be heavier than air, but it will not be
an aeroplane. It will have no wings. It will be substantial,
solid, stable. You cannot have a stable airplane. The gyroscope
can never be successfully applied to the airplane, for it would
give a stability that would result in the machine being torn
to pieces by the wind, just as the unprotected aeroplane on the
ground is torn to pieces by a high wind. "My flying machine
will have neither wings nor propellers. You might see it on the
ground and you would never guess that it was a flying machine.
Yet it will be able to move at will through the air in any direction
with perfect safety, higher speeds than have yet been reached,
regardless of weather and oblivious of 'holes in the air' or
downward currents. It will ascend in such currents if desired.
It can remain absolutely stationary in the air even in a wind
for great length of time. Its lifting power will not depend upon
any such delicate devices as the bird has to employ, but upon
positive mechanical action. "You will get stability through
gyroscopes?" I asked. "Through gyroscopic action of
my engine, assisted by some devices I am not yet prepared to
talk about," he replied. "Powerful air currents that
may be deflected at will, if produced by engines and compressors
sufficiently light and powerful, might lift a heavy body off
the ground and propel it through the air," I ventured, wondering
if I had grasped the inventor's secret. Dr. Tesla smiled an inscrutable
smile. "All I have to say on that point is that my airship
will have neither gas bag, wings nor propellers," he said.
"It is the child of my dreams, the product of years of intense
and painful toil and research. I am not going to talk about it
any further. But whatever my airship may be, here at least is
an engine that will do things that no other engine ever has done,
and that is something tangible.
Nikola Tesla
Science
& Mathematics
The
Uncle Taz Library