Despite the protests of the majority of interested persons, however,

Cocking and a companion named Green made the ascent at the appointed

time. After rising to a certain height the parachute was cast off,

the parachute's car containing the inventor, while Green remained in

the balloon. Instead of sailing slowly toward the earth, however, the

parachute fell rapidly, with an oscillating movement, gaining speed and

jerking violently as it descended, until finally when several hundred

feet in the air, Cocking was thrown from the car and dashed to pieces,

while the wreck of the parachute landed a few yards away. Thus the

predictions of the majority came true, although as we know now, the

cause of the tragedy was due to faulty material rather than the design

of the machine. For the American aeronaut, Wise, demonstrated a little

later that parachutes built on the same principle as that of Cocking

could be used successfully.

As we have seen, most of the flying-machines attempted heretofore

took for their model the bird with flapping wings. There were certain

persons, however, who had observed that this flapping movement was not

essential to flight--that certain large-winged birds, such as buzzards

and hawks, were able to soar in any direction at will, holding their

wings rigidly. It was evident, therefore, that shape, position, and

construction of the bird's wing played quite as important a part as the

flapping movement. The lifting power of plane surfaces, or aeroplanes,

was also carefully studied in this connection and in 1842 the inventor,

Henson, constructed a flying-machine utilizing this aeroplane

principle, his machine having thin, fixed surfaces, slightly inclined

to the line of motion, and supported by the upward pressure of the air

due to the forward movement.

Everyone will remember the distance to which a skilful juggler can

project an ordinary playing-card by giving it a certain inclination

in throwing. It will travel upward or on a level, and continue this

direction until the force of the movement of throwing is exhausted.

Obviously, if this force were self-contained in the card--if it could

continue rotating and moving forward--it could fly indefinitely. Henson

had studied and experimented with these miniature aeroplanes, and was

convinced that if the same principle that governed their flight were to

be applied to larger machines, practical flying-machines could be made.

"If any light and flat, or nearly flat, article," he wrote, "be

projected edgeways in a slightly inclined position, the same will rise

on the air till the force exerted is expended, when the article so

thrown or projected will descend; and it will readily be conceived that

if the article possessed in itself a continuous power or force equal to

that used in throwing or projecting it, the article would continue to

ascend so long as the forward part of the surface was upward in respect

to its hinder part, and that such article, when the power was stopped,

or when the inclination was recovered, would descend by gravity only if

the power was stopped, or by gravity, aided by the force of the power

contained in the article, if the power be contained, thus imitating the

flight of a bird."

But when Henson attempted to fly in his elaborately planned and

constructed flying-machine, it proved a complete failure. It showed

a tendency to rise, but its lifting power was insufficient for the

weight of the engine driving the propellers. It was evident, however,

that if the power of the engine could be sufficiently increased, or,

what amounts to the same thing, its weight sufficiently lightened, a

machine built on the aeroplane principle could be made to fly. But at

that time the lightest type of engine was a crude, heavy machine, and

for the moment nothing more was attempted in producing a mechanical

flying-machine propelled by steam.

Meanwhile the possibility of producing a dirigible balloon was again

brought into prominence by the suggestion of two aeronauts, Scott and

Martainville, to change the shape of the envelope of the balloon.

Hitherto, all balloons had been made globular or pear-shaped--shapes

that offered great resisting surfaces to the atmosphere. Now it was

proposed to make them in the form of long, horizontal cylinders, with

pointed ends, these cigar-shaped, or boat-shaped balloons offering

much less resistance. But here, as in the case of the flying-machine,

engines that were sufficiently strong to work the propellers were found

to be too heavy for the balloon to lift. Meanwhile the aeroplane idea

was brought into prominence from an unexpected quarter.

Among the numerous observers in the middle of the century who had noted

the soaring power of birds, was a French sea-captain named Le Bris. On

his long voyages he had studied the movements of the great albatross,

which, with wings rigidly distended, outsailed the swiftest ship

without any apparent exertion. Anxious to study the wing-mechanism of

this bird, the captain, overcoming the scruples of the mariner against

killing the sacred sea-rover, shot one of the birds. On removing a wing

and spreading it in the wind he thought that it had a very appreciable

tendency to pull forward into the breeze, and tended to rise when the

wind was strong. Convinced that by duplicating the shape of the bird he

could construct a successful flying-machine, Le Bris set to work and

succeeded in producing a most remarkable "air-ship."

The body of this machine, which was supposed to correspond to the body

of the bird, was made boat-shaped, and was about thirteen feet long and

four feet wide, being broadest at its prow, in imitation of the breast

of the bird. The front part was decked over, something like the bow of

the modern torpedo-boat, and through this deck protruded a small mast

which was used for supporting the pulleys and cords used in working

the machinery of the wings. Each wing was about twenty-five feet long,

so that the entire spread of the machine was fifty feet. There was

a tail-like structure so hinged that it could be used for steering

up, down, and sidewise, the total area of surface presented to the

atmosphere being something over two hundred square feet, although the

entire "albatross" weighed something less than a hundred pounds.

The front edges of the wings were made of pieces of wood fashioned

like the wings of the albatross, and feathers were imitated by a frame

structure covered with canton flannel. The front edges of the wings

could be given a rotary motion to fix them at any desired angle by an

ingenious device worked by two levers. In operating this artificial

bird the captain proposed to stand in the boat and control its flight

by these sets of levers and by balancing his body.

Having full confidence in the ability of his invention to soar once

it had been given an initial velocity, the captain selected a morning

when a good breeze was blowing and hired a cart-driver to carry him

out into the neighboring fields. The machine was placed horizontally

upon the cart and fastened to it with a rope which could be loosened

by the pulling of a slip-knot held by the captain, who took his

position in the boat. On reaching the open country the driver put his

horse into a brisk trot when, the levers controlling the wings being

set, the machine rose gracefully into the air and travelled forward a

distance of perhaps a hundred yards. At this moment the running-rope in

some unaccountable manner became wound about the body of the driver,

hauling him unceremoniously from his seat, and dangling him writhing

and shrieking at the end of the rope, several feet above the ground.

As it happened, his weight was just sufficient to counterbalance the

wind, so that acting in the capacity of the tail of a kite, he assisted

materially, if involuntarily, in keeping the artificial bird in flight.

When the captain became aware of what was going on below, he altered

the angle of the wings and came slowly to the earth, descending without

accident either to himself or to his machine. All things considered,

this was a remarkable performance, and it was so considered by people

in the neighborhood, who made a hero of the gallant mariner. His next

attempt, however, was less successful. Something went wrong with the

machine shortly after starting, landing the inventor in a stone-quarry

with a broken leg and a shattered machine. This accident also shook the

courage of the captain, and for several years he made no more attempts

at flight, confining his attention to sailing a coasting-vessel. But

his faith in his "albatross" never wavered, even if his courage did for

a time, and in 1867 he began building a more elaborate machine, aided

by public subscriptions. The outlook for this new device seemed very

promising, several fairly successful flights of perhaps two hundred

yards having been made, when a sudden gust of wind catching up the

machine one day during the momentary absence of the inventor, dashed

it to pieces upon the ground. This was the final blow to the hopes

of Captain Le Bris, who made no further attempts, his means and his

energies being entirely exhausted.

GIFFARD, "THE FULTON OF AERIAL NAVIGATION"

Meanwhile the advocates of the dirigible balloon had not remained idle,

many of them attempting to utilize the principle of the aeroplane

in connection with a balloon. Some of these machines were of most

fantastic design, but one in particular, that of Mr. Henri Giffard,

succeeded so well, and proved to be dirigible to such an extent, that

Giffard is sometimes referred to by enthusiastic admirers as "the

Fulton of aerial navigation." In principle, and indeed in general

appearance, this balloon was not unlike some of the balloons built by

Santos-Dumont fifty years later. It had the now-familiar cigar shape,

common to most modern dirigible balloons; and beneath was suspended a

car carrying a steam-engine that worked a screw propeller. The rudder,

placed at the stern just below the balloon in a position corresponding

to the rudder of a ship, was a large canvas sail set in a frame.

The envelope of the balloon was one hundred and fifty feet long and

forty feet in diameter and contained about ninety thousand cubic feet

of coal-gas. To lessen the danger of igniting this from the engine,

Giffard arranged the chimney so that it pointed downward, and suspended

it some forty feet below the envelope.

On September 24, 1852, he rose from the Paris Hippodrome, and succeeded

in making a headway of from five to seven miles an hour in the face

of a strong wind. In response to the rudder his balloon performed

some difficult evolutions, turning right or left at the will of

the operator. He continued his maneuvers for some time, and then

extinguishing his fire, opened the valve and returned safely to the

ground. This was a great victory for the advocates of the dirigible

balloon, and was indeed a performance that has not until recently been

surpassed in the fifty years that have intervened since that time.

But despite this initial success, Giffard soon renounced the field of

aeronautics, and no worthy successor appeared to take his place for

more than a quarter of a century.

THE VOYAGES OF THE _GIANT_

One of the most remarkable balloons ever constructed, and one of the

most remarkable voyages ever made in any balloon, was that of the

mammoth aerostat constructed by the noted Parisian photographer,

Nadar, in 1863. Nadar belonged to the school of aviators who opposed

the principle of the balloon as against that of the aeroplane, and his

idea in constructing this leviathan balloon was simply for the purpose

of raising money so that he might build a practical flying-machine,

constructed on the aeroplane principle, and which, he declared,

would revolutionize air navigation. The _Giant_, he said, would be

the last balloon ever constructed, as thereafter air-ships, made on

the principle of the one he was about to construct, would supplant

balloons entirely. His plan was to make the ascent in the _Giant_ from

some large enclosed field near Paris, and the admission price of one

franc to be charged for entering the field was to supply funds for

defraying the expense of building the _Giant_, the surplus to be used

in constructing his flying-machine.

In making the _Giant_ twenty-one thousand yards of silk were used,

the balloon being over two hundred feet in height, with a lifting

capacity of nine thousand pounds. It was built as a double balloon,

one within the other, this being the idea of the aeronaut, Louis

Godard, as a means of preserving the excess of gas produced by dilation

at different altitudes, instead of losing this excess as was usual

with balloons constructed in the ordinary manner. But perhaps the

most interesting thing about this balloon was the structure of the

car and its contents. Like the ordinary car it was constructed of

wicker work, but was of the proportions of a small house, being built

two stories high, with an upper platform like the deck of a ship,

on which the passengers could stand. In the two floors below were a

saloon, compartments for scientific instruments, sleeping-cabins, and

practically all the conveniences of a small, modern house. In the car

and suspended about it were wheels, guns, a printing-press, cameras,

cages of carrier-pigeons, baskets of wine and provisions, games, and an

"abundant supply of confectionery."

The first ascent was made from the Champs de Mars, and twenty-five

thousand persons paid the admission fee to witness it. This did not by

any means represent the number of persons on the field, as the barriers

were broken down in many places early in the day, and a majority of

the spectators thus gained free admission. Fifteen persons made the

ascent upon this occasion, but instead of making a protracted voyage as

intended at first, the balloon was brought to the earth at nine o'clock

in the evening only a few leagues from Paris. It is said that this

landing was made contrary to the wishes of Nadar, but in deference to

the opinion of the Godard brothers, who believed that the balloon was

being carried out to sea, whereas, in point of fact it was travelling

due east, directly away from the Atlantic.

Three weeks later the second ascent was made, on this occasion eight

instead of fifteen persons starting on the voyage. These were under

the immediate command of Nadar, whose position was that of the captain

of a ship on the high seas, and whose authority none might presume to

question. A set of rules governing the conduct of those on board and

setting forth explicitly the authority of the captain was posted in

the cabin, the nature of some of these giving a cue to the peculiar

attitude of mind of the originator of the scheme. For example, it was

ordered that "Silence must be absolutely observed when ordered by

the captain." "All gambling is expressly prohibited." "On landing no

passenger must quit the balloon without permission duly acquired from

the captain."

The ascent was again successful, the balloon travelling in a

northeasterly direction during the night, all the passengers remaining

awake and alert, having constantly in mind the danger of falling into

the sea. The following morning on descending to a lower altitude

through the clouds, the voyagers found that they were passing the

border of Holland, near the sea. At this point an attempt was made to

land, but a violent gale having arisen, the anchor cables were broken,

and the car was dragged along the surface of the ground at terrific

speed, striking and rebounding into the air, dragging through marshes

and rivers, bruising and battering the occupants who were unable either

to leave the balloon or to check its flight. As they were whirling

across the country in this manner an immense forest came into view

directly in their path, and believing that when this was reached every

occupant of the car would be dashed to pieces against the trees, they

decided to take their chances by leaping. One after another they

jumped, striking the earth and turning over and over, breaking bones,

and mangling faces and bodies. The only female occupant of the car,

Mrs. Nadar, was fortunate in alighting in a river without serious

injury. Others received only slight bruises or a severe jolting while

the most unfortunate, M. St. Felix, had a broken arm, a dislocated

ankle, and numerous cuts and bruises.

Later the _Giant_ was captured many miles farther on and returned to

its owners in Paris. Subsequently it made numerous voyages, none of

which was particularly profitable, however, so that the purpose for

which it was designed was not fulfilled, and Nadar's proposed air-ship

was never constructed.

While the _Giant_ was the largest balloon hitherto constructed, it

broke no records either for speed attained or distance travelled, and

much more notable performances in this respect had been made before its

time and have been made since. Thus, one of Coxwell's balloons traveled

from Berlin in the direction of Dantzig, covering the distance of one

hundred and seventy miles in three hours. This was in 1849; and in the

same year M. Arban crossed the Alps from Marseilles to Turin, covering

the distance of four hundred miles in eight hours. In July, 1859,

the American aeronaut, John Wise, sailed from St. Louis, Missouri,

to Henderson, in New York State, in nineteen hours, travelling eight

hundred and fifty miles at the rate of forty-six miles an hour. This

was the longest voyage ever made until the time of the balloon-races

started from the Paris Exposition, in 1900. On this occasion Conte de

la Vaux, starting from Paris, remained in the air thirty-five hours and

forty-five minutes, landing at Korosticheff, in Russia, 1193 miles from

the starting-point, thus breaking all previous records.

EARLY WAR-BALLOONS AND DIRIGIBLE BALLOONS

Despite the fact that the "aviators"--the aeronauts whose efforts

were directed to flight by mechanical means in imitation of birds,

or by the use of what are now called aeroplanes--were in the field

centuries before the balloon was invented, from the time of the first

Montgolfier balloon until very recently, the balloonists had shown

their rivals a clean pair of heels in practical results. A dirigible,

man-carrying balloon that can be guided under favorable conditions, and

can maintain itself in the air for any considerable length of time, was

an accomplished fact at least five years before the practical aeroplane

flying-machine. Yet the majority of scientists had become convinced

several years before their convictions were verified by actual

demonstration, that some type of mechanical flying-machine--a machine

that is heavier than the atmosphere and that maintains itself by some

mechanical means--was the only one likely to solve the question of

aerial flight. Yet thus far balloons have rendered more actual service

to man than flying-machines.

It will be recalled that balloons were used for making military

observations during the French Revolution; and they were used for

similar purposes in several of the Continental wars during the first

half of the nineteenth century. After that time, however, interest

in their use for this purpose flagged somewhat until the time of the

Crimean War, when their usefulness was again demonstrated, as it was in

the American Civil War which followed shortly after.

But it was not until the Franco-Prussian War that the one thing for

which the Montgolfiers had predicted their usefulness in warfare--that

of sending messages out from a closely besieged city--was put to

practical test. During the siege of Paris by the Germans in 1870-71,

when every other possible means of communication had been cut off, the

Parisians still kept in communication with the outside world by means

of balloons and carrier-pigeons. On September 23rd, the first ascent

of the siege was made by the aeronaut Durouf, who carried a large

number of despatches from the city, landing near Evreux, after being

in the air about three hours. The success of this journey and several

others that quickly followed led the French Government to establish

a regular balloon-post, and to undertake the manufacture of balloons

for this purpose. The mere matter of balloon construction offered no

difficulty but a more serious one was met in the lack of experienced

aeronauts. In this emergency, however, it occurred to the authorities

that sailors, accustomed to climbing about at dizzy heights, might be

taught to take the place of trained aeronauts. This experiment proved

most successful, and in subsequent voyages these mariners maintained

their reputation for daring undertakings. Between September and January

sixty-four balloons were sent up, all but seven of which fulfilled

their mission and delivered their despatches; and the total number of

persons leaving Paris in balloons during the siege was one hundred and

fifty-five. These carried with them a total of nine tons of despatches

and something like three million letters, the speed with which these

journeys were made ranging from a minimum of twenty miles an hour to a

maximum velocity, in one instance, of eighty miles.

Shortly after this balloon-post was established, the Germans came into

possession of the new Krupp long-range rifle, with which they succeeded

in bringing down several of the balloons. Companies of Uhlans, the

swiftest cavalry of Germany, scoured the country constantly, and kept

such a sharp lookout that, as the German lines were extended, it became

difficult for the balloons to make their way over them in daylight.

Night voyages, therefore, became necessary; but naturally these

were extremely dangerous, and many of them had dramatic and tragic

terminations. One of the longest and most famous of these voyages was

that of the balloon named the _Ville d'Orléans_, which left Paris

about midnight of November 24th. As a strong wind was blowing from

the north at the time, it was hoped that the balloon would descend

in the vicinity of Tours. The first intimation that the voyagers had

that there was a deviation from this course was the sound of the

waves breaking against the shore beneath them. At this time they were

in a thick mist, and it was not until some time after daybreak that

this mist cleared away sufficiently for them to get an idea of their

surroundings. Then they found, to their horror, that they were over a

large body of water, out of sight of land, in what part of the world

they had not the slightest idea. The balloon appeared to be drifting

rapidly, and from time to time they passed over vessels, which were

frantically signaled by the voyagers. No notice was taken of these

signals except by one vessel, which responded by firing several shots

which went wide of the mark. The balloon continued on its course

northward until late in the day when land was sighted lying to the

northeast. By this time the ballast in the car had been entirely

expended, and the balloon, which had been sinking gradually for several

hours, seemed about to plunge into the ocean. In this extremity a heavy

bag of despatches was thrown out, and the balloon thus lightened again

rose to a considerable height, where another current of air carried it

over the land.

A successful landing was made in Norway, in a desolate but friendly

region, where the balloonists were treated with the greatest kindness.

The balloon and its contents were subsequently secured, and all the

despatches delivered to their proper destinations, except, of course,

the one package that had been thrown out as ballast.

A week after the eventful voyage of the _Ville d'Orléans_ a still

more unfortunate ascent was made by a sailor named Prince, in the

balloon called the _Jacquard_. As the ropes releasing this balloon

were cut, the enthusiastic mariner, standing in his car and extending

his hand toward the crowd, shouted dramatically, "I go upon a great

voyage!" He did--and on one much greater than he anticipated--for the

balloon was blown out to sea and lost. As he was passing over England

after successfully crossing the Channel, he threw out his package of

despatches, but this so lightened his balloon that it mounted quickly

and was soon far out over the Atlantic. It was never heard of again.

But the life of the enthusiastic voyager was not given in vain, for

most of the despatches eventually reached their destination.

Although, as has been seen, the balloons sent out of Paris were not of

the dirigible kind, and were entirely dependent upon the caprice of the

winds, they fulfilled their missions quite as well as could be expected

under the circumstances. In fact, there was small chance of failure,

starting as they did from a central point, and being almost certain of

success no matter what direction was taken, except, indeed, the one

that would blow them over the German frontier. But the other part of

the problem--the sending of balloons from the outside into Paris--was

an entirely different proposition. So different, and so difficult, in

fact, that it was never accomplished, although attempted several times.

But the millions of people in Paris, shut off completely from the

outside world, were just as anxious to receive news as to send it. In

attempting to establish communication from without, therefore, one

balloon leaving the city in the early days of the siege, carried with

it some trained dogs in the hope that they would make their way back to

the city through the German lines. But either they lost their way, or

were captured by the enemy, for nothing was ever heard of them after

starting on the return trip. In this extremity the members of the

"Société Colombophile" came forward with the offer of the use of their

homing-pigeons. The society had a large number of these birds, trained

to return to their cotes from long distances, and the experiment of

sending return despatches with them was tried at once. Three birds

were first sent out in one of the despatch-balloons, and within

sixteen hours after starting these had all returned to the capital,

bearing despatches. During the next few days a score more pigeons were

sent out, eighteen of which returned safely with their messages; and

thereafter a regular pigeon-post was organized.

As the weight that a pigeon is able to carry in its flight is extremely

small, microscopic photography was resorted to, so that, although each

bird carried only a single quill in which were rolled thin collodion

leaves, the whole weighing only fifteen grains, the amount of printed

matter thus carried was sometimes more than is contained in an ordinary

volume.

By photographic methods, thirty-two thousand words, or about half an

ordinary volume, were crowded upon a pellicule two inches long by one

and one-quarter inches wide, and weighing about three-quarters of a

grain! Twenty of these, representing six thousand words, or twice the

amount of printed matter contained in such a book as Scott's _Ivanhoe_,

or Prescott's _Conquest of Mexico_, were carried by each pigeon. One

bird carried forty thousand complete messages on a single trip.

When the bird arrived at its cote, the quill was secured and taken

to the government office, where the little leaflets were carefully

removed, placed in an enlarging optical apparatus, thrown upon a screen

with a magic lantern, and copied. The messages were then distributed to

their destination about the city.

THE DIRIGIBLE BALLOON ACHIEVED

By this war, France, the home of the balloon, was brought keenly to

realize the advantages and the limitations of such flying-machines;

and it was but natural, under the circumstances, that as soon as peace

was restored, efforts should be made there to produce a dirigible

balloon, or some other form of dirigible flying-machine. Giffard, as

we have seen, had been fairly successful; and now M. Dupuy de Lome,

chief naval constructor of France, took up the problem. He constructed

a balloon with a cigar-shaped envelope one hundred and twenty feet

long and fifty feet in diameter. Beneath this was a rudder placed in

the same position as that of a ship; and suspended still further below

was a large car fitted with a two-bladed screw-propeller, thirty feet

in diameter. Manual labor was to be used for turning this screw, two

relays of four men each relieving each other at the work. An ascent

was made in February, 1872, with fourteen persons in the car, who,

by working in relays, demonstrated that a speed of about seven miles

an hour could be maintained in any direction in still air. As the

wind was blowing about thirty miles an hour at the time, however, the

course of the balloon could only be deflected, and the main object of

the ascent--the return to Paris--could not be accomplished. In short,

De Lome's balloon demonstrated little more than had been accomplished

by Giffard with his steam-driven balloon. Both had shown that with

sufficient power the balloon could be made to travel in any direction

in still air, but neither had been able to make headway against a

strong wind.

It was estimated at the time of Dupuy de Lome's ascent, that had a

steam-engine of a weight corresponding to that of the eight workmen

been used, at least twice the power could have been obtained. But

steam was considered too dangerous, and some other motive power which

combined lightness with power seemed absolutely essential. The electric

motor gave promise of success in this direction, and in 1883 the two

Tissandier brothers in France applied such a motor to a balloon that

was able to make headway against a seven-mile breeze, but was still far

from fulfilling the requirements of an entirely dirigible balloon. Two

years later the motor-driven balloon _La France_, of Renard and Krebs,

attained a speed of fourteen miles an hour, and showed a distinct

advance over all preceding models.

Meanwhile motors were being reduced in weight and increased in power,

and the hearts of aviators and balloonists were cheered by the fact

that the light metal, aluminum, was steadily growing cheaper. Visions

of an all-aluminum balloon were constantly before the minds of the

inventors, and in 1894 such dreams took practical form in a balloon

whose construction was begun by Herr Schwartz, under the auspices

of the German Government. This balloon was of most complicated

construction, depending for its lifting power upon the gas-filled

aluminum tank, but utilizing for its steering-gear many of the features

of the aeroplane. It was essentially a balloon, not a flying-machine,

however, with a ten to twelve horse-power benzine-engine actuating four

propelling screws.

[Illustration: TWO FAMOUS FRENCH WAR BALLOONS.

The lower figure the dirigible war balloon "La Patrie," which

manœuvered on the Eastern boundary of France, and which was blown

away and lost taking a northwesterly direction which probably landed

it ultimately in the Arctic Sea--in 1908. The upper figure represents

M. Deutsch's dirigible balloon "Ville de Paris" which was sent to the

frontier to take the place of the lost "Patrie."]

Before the balloon was completed Herr Schwartz died, but his plans were

known to his wife, and, although considerably altered, were carried to

completion. When all was finished, Herr Jaegels, an engineer who had

had no experience as an aeronaut, volunteered to make an ascent and

this metal ship-of-promise was launched. At first it rose rapidly and

appeared to be making good progress against a strong wind; but suddenly

it stopped, descended rapidly, and was smashed to pieces, the aeronaut

saving himself by jumping just before it touched the ground. It

developed later that he had lost control of the machine, simply because

the machinery was too complicated for a single operator to handle. On

discovering this, Herr Jaegels, confused for the moment, threw open the

valve, causing the balloon to descend too rapidly. Thus the fruit of

years of study and labor and the expenditure of fifty thousand dollars

in money resulted in only about six minutes of actual flight.

To most persons this experiment of the aluminum balloon would seem to

have been a dismal failure, but it was not so regarded by the advocates

of the dirigible balloon. The flight of the balloon, to be sure, was

far from a success; but this was attributed to improper management

rather than to any inherent defect in the balloon itself, or in the

principle upon which it was constructed. Instead of being discouraged,

therefore, the school of balloonists, who had lost some of their

prestige of late by the performances of the flying-machines of Maxim

and Langley, undertook, through their enthusiastic representative,

Count Zeppelin, the construction of the largest, most expensive,

and most carefully built dirigible balloon heretofore constructed.

This balloon was of proportions warranting the name of "air-ship."

The great cigar-shaped body was almost four hundred feet in length,

and thirty feet in diameter--the proportions of a fair-sized ocean

liner--and like the hull of its ocean prototype, was divided into

compartments--seventeen in number, and gas-tight. Its frame-work was of

aluminum rods and wires, and the skin of the envelope was made of silk,

coated with india-rubber. It was equipped with four aluminum screws,

and two aluminum cars were placed below the body at a considerable

distance apart. The motive power was supplied by benzine motors,

selected because of their lightness.

The company for constructing this balloon was capitalized at about two

hundred thousand dollars, the cost of the shed alone, which rested on

ninety-five pontoons on the surface of the lake of Constance, near the

town of Manzell, being fifty thousand dollars. July 2nd, 1910, the

count and four assistants in the cars, started on the maiden voyage.

The balloon rose and made headway at the rate of eighteen miles an

hour, responding readily to the rudder, but soon broke or deranged

some of the steering-gear so that it became unmanageable and descended

at Immerstaad, a little over three miles from the starting-point.

Considering the amount of thought, care, and money that had been

expended upon it, its performance could hardly be looked upon as a

startling success. By the advocates of the aeroplane principle it was

considered an utter failure.

[Illustration: THE ZEPPELIN DIRIGIBLE BALLOON.

Count Zeppelin's famous balloons are of the semi-rigid type, being

cased in thin loops of aluminum. The wing-like projections at the

sides add greatly to the stability and dirigibility of the balloon.

The problem of housing has been met by erecting a structure over the

water. It is planned to have a balloon house that will revolve and thus

facilitate the introduction of the balloon whatever the direction of

the wind. With the above stationary house this is a difficult manœuvre

if the wind chances to blow laterally.]

But while Count Zeppelin was experimenting with his ponderous leviathan

air-ship, a kindred spirit, the young Brazilian, M. Santos-Dumont,

was making experiments along similar lines, but with balloons that

were mere cockle-shells as compared with the German monster. The

young inventor had come to Paris from his home in South America

backed by an immense fortune, and by a fund of enthusiasm, courage,

and determination unsurpassed by any aerial experimenter in any age.

He began at once experimenting with balloons of different shapes,

with screws and paddles, and, perhaps most important of all, with

the new, light petroleum-motors just then being introduced for use

on automobiles, electricity not having proved a success in aerial

experiments.

His first balloon, _No. 1_, built in 1898, was devoid of any

particularly novel features. His _No. 2_ showed some advancement,

and his _No. 3_, while a decided improvement, still came far short

of answering the requirements of a dirigible balloon. But the young

experimenter was learning and profiting by his failures--and,

incidentally, was having hairbreadth escapes from death, meeting with

many accidents, and being severely injured on occasion.

About this time a prize of one hundred thousand francs was offered

by M. Deutsch to the aeronaut who should ascend from a specified

place in a park in Paris, make the circuit of the Eiffel Tower, and

return to the starting-point within half an hour. With the honor of

capturing this prize as an additional incentive, Santos-Dumont began

the construction of his fourth balloon, the _Santos-Dumont No. 4_.

In this balloon everything but bare essentials was sacrificed to

lightness, even the car being done away with, the aeronaut controlling

the machinery and directing the movements of the balloon from a bamboo

saddle. But an accident soon destroyed this balloon, and a fifth was

hastily constructed. With this the enthusiastic aeronaut showed that

he was almost within grasping distance of the prize in a series of

sensational flights between the first part of July and the first week

in August. The tower was actually rounded, but on the return trip

the balloon collided with a high building in the Rue Alboni and was

wrecked, the escape of the aeronaut without a scratch being little

short of miraculous.

Nothing daunted, the inventor began the construction of _Santos-Dumont

No. 6_ immediately, finishing it just twenty-eight days after the

construction of _No. 5_. A peculiarity of this balloon was that it

was barely self-sustaining except when forced through the air by the

propeller. The long cigar-shaped gas-bag was relatively small, and was

filled to its limit of capacity with gas, while the lifting power was

counterbalanced by the operator, car, engine, and ballast, so that the

entire structure weighed practically the same as the air it displaced.

At the stern was a powerful propeller. Obviously, then, if the long

spindle-shaped machine was tilted upward at the forward end, and the

propeller started, it would be driven upward; while if the forward end

was lowered the propeller would drive it downward. If it was balanced

so as to be perfectly horizontal, it would be forced forward in a

horizontal direction. Deflections to right and to left were obtained by

the ordinary type of vertical rudder; and thus any direction could be

taken.

[Illustration: AN ENGLISH DIRIGIBLE BALLOON.

The photograph here reproduced gives a very vivid impression of the

cumbersome nature of balloons of this modern type, and suggests the

difficulties to be met in housing them safely when not in use.]

To obtain the desired angle of inclination, Santos-Dumont made

use of a sliding weight, and with this he guided his balloon upward

and downward by shifting its position. Thus, although this balloon

was a veritable balloon rather than a "flying-machine" proper, it

really lacked the one essential common to balloons: it would not rise

until propelled by mechanical means. It lacked the requisite of the

flying-machine, however, in that it was not "many times heavier than

the air." After giving this new balloon several preliminary trials,

which included such exciting incidents as collisions with a tree

in the Bois du Boulogne, an official attempt was made on October

29th, 1800. Above the heads of the gaping thousands, who, to a man,

wished the daring navigator success, the balloon rounded the tower,

and in twenty-nine minutes and thirty seconds from the moment of

starting--thirty seconds less than the prescribed time-limit--the trip

was successfully terminated.

This voyage must be considered as marking an epoch in aerial

navigation. The dirigible balloon was accomplished. A decided step

forward in the conquest of the air had been made, although from a

practical standpoint this step was confessedly a short one. For while

_No. 6_ could be propelled in any direction under ordinary conditions,

carrying a single passenger, it was on the whole more of a toy

ship than a practical sailing-craft. Nevertheless, its performance

was a decided victory for the balloon over the flying-machine.

No flying-machine of whatever type had ever even approached the

performance of _Santos-Dumont No. 6_, which had carried a man on a

voyage in the air, traveling with the wind, against it, and with the

wind on either quarter at every possible angle at various times during

the journey. And yet there were few scientists, indeed, if any, who

considered that the problem of aerial navigation was solved; and to

a large number Santos-Dumont's performance seemed little more than

an extension of Giffard's idea, made possible by improved machinery

not available half a century ago. To them it was the triumph of the

energy, skill, and courage of an individual, not the triumph of a

principle--which, after all, is the absolute essential.

[Illustration]

[Illustration: ENGLISH (LOWER FIGURE) AND AMERICAN DIRIGIBLE WAR

BALLOONS AND A WRIGHT AEROPLANE.

The above figures are introduced on one page for the purpose of

comparison and contrast. The American balloon is the Baldwin airship.

The essential clumsiness of a lighter-than-air craft, as contrasted

with the relative gracefulness and manageableness of the aeroplane, is

strikingly suggested by this illustration.]

Since the successful performance of Santos-Dumont in rounding the

Eiffel Tower many other dirigible balloons have been constructed,

not only in America and in Europe by various inventors, but by the

Brazilian aeronaut himself. The most remarkable of these is the

_Zeppelin II_, the fifth creation of the indomitable Count Zeppelin.

In principle and general lines of construction this balloon closely

resembles the one described a few pages back. Its best performance,

however, is more remarkable. Starting from Lake Constance on the night

of May 29th, 1909, and sailing almost directly northward regardless

of air currents, the balloon reached Bitterfield, a few miles beyond

Leipzig, four hundred and sixty-five miles from the starting-point,

the following evening. Turning back at this point, without alighting,

it had almost completed its return trip, when on coming to the ground

for a supply of fuel it was injured by collision with the branches of a

tree. The injury sustained, while delaying and marring the voyage, did

not prevent the balloon from completing its eight-hundred-and-fifty

mile voyage, and establishing a new record for dirigibles.

This and sundry other flights amply demonstrated the dirigibility and

relative safety of the balloon under varying atmospheric conditions.

But the difficulties that attend the management of such a craft when

not high in air were again vividly illustrated when, in April, 1910,

the Zeppelin II., was totally wrecked while at anchor by the force of a

gale which it might easily have outridden had it been beyond the reach

of terrestrial obstacles.

X

THE TRIUMPH OF THE AEROPLANE

Although the dirigible balloon in the hands of Santos-Dumont gained

a decisive victory over all mechanical methods of flight theretofore

discovered, even the inventor himself considered it rather as a means

to an end, than the end itself. That end, it would seem, must be a

flying-machine, many times heavier than the atmosphere, but able by

mechanical means to lift and propel itself through the air. The natural

representative of this kind of flying-machine, the bird, is something

like a thousand times as heavy as the air which its bulk displaces.

The balloon, on the other hand, with its equipments and occupants,

must necessarily be lighter than air; and as the ordinary gas used for

inflating is only about seven times lighter than the atmosphere, it can

be readily understood that for a balloon to acquire any great amount

of lifting power it must be of enormous proportions. To attempt to

force this great, fragile bulk of light material through the atmosphere

at any great rate of speed is obviously impossible on account of

the resistance offered by its surfaces. On the other hand, any such

structure strong enough to resist the enormous pressure at high speed

would be too heavy to float.

[Illustration: THE AEROPLANE OF M. SANTOS DUMONT.

M. Santos Dumont's chief fame as an aviator is based on his flights

with a dirigible balloon. He has experimented extensively, however,

with the heavier-than-air type of machine, though none of his flights

with this apparatus has been record-breaking.]

These facts are so patent that it is but natural to inquire how

the balloonists could ever have expected to accomplish flight at

more than a nominal rate of speed; and, on the other hand, it might

be asked, naturally enough, how the aviators expected to fly with

aeroplane machines at least a thousand times heavier than the air.

In reply, the aviators could point to birds and bats as examples of

how the apparently impossible is easily accomplished in nature; while

the balloonists could simply point to their accomplished flights as

practical demonstrations. The aviators could point to no past records

of accomplishments, but nevertheless they had good ground for the faith

that was in them, and as we shall see were later to justify their

theories by practical demonstrations.

Everybody is aware that there is an enormous difference in the

lifting power of still air and air in motion, and that this power is

dependent upon velocity. The difference between the puff of wind that

barely lifts a thin sheet of paper from the table, and the tornado

that uproots trees and wrecks stone buildings, is one of velocity.

Obviously, then, moving air is quite a different substance from still

air when it comes to dealing with aeronautics.

One of the most familiar examples of the lifting power of moving air

is that of the kite. An ordinary kite is many times heavier than the

air and has no more tendency to rise in the air than a corresponding

weight of lead under ordinary conditions. Yet this same kite, if held

by a string with its surfaces inclined to the wind at a certain angle,

will be lifted with a force proportionate to the velocity of the wind

and the size of the surfaces. On a windy day the kite-flyer holding

the string and standing still will have his kite pushed upward into

the air by the current rushing beneath its surface. On a still day he

may accomplish the same thing by running forward with the kite-string,

thus causing the surface of the kite to "slide over" the opposing

atmosphere. In short, it makes no difference whether the air or kite is

moving, so long as the effect of the current rushing against the lower

surface is produced. Obviously, then, if in place of the kite-flyer

holding the string and running at a certain speed, some kind of a motor

could be attached to the kite that would push it forward at a rate of

speed corresponding to the speed of the runner, the kite would rise--in

short, would be converted into a flying-machine.

Looked at in another way, the action of the air in sustaining a body

in motion in the air has been compared by Professor Langley to the

sustaining power of thin ice, which does not break under the weight

of a swiftly gliding skater, although it would sustain only a small

fraction of his weight if he were stationary. Supposing, for example,

the skater were to stand upon a cake of ice a foot square for a single

second; he would sink, let us say, to his waist in the water. On a cake

having twice the surface area, or two square feet, he would sink only

to his knees; while if the area of the cake is multiplied ten times

the original size, he would scarcely wet his feet in the period of a

second. Now supposing the cake to be cut into ten cakes of one square

foot each, placed together in a line so that the skater could glide

over the entire ten feet in length in one second. It is evident that

he would thus distribute his weight over the same amount of ice as if

the cakes were fastened together in a solid piece.

"So it is with the air," says Professor Langley. "Even the viewless air

possesses inertia; it cannot be pushed aside without some effort; and

while the portion which is directly under the air-ship would not keep

it from falling several yards in the first second, if the ship goes

forward so that it runs or treads on thousands of such portions in that

time, it will sink in proportionately less degree; sink, perhaps only

through a fraction of an inch."

It is evident, therefore, that if, at a given speed, the horizontal

wings of an air-ship would keep it from falling more than a fraction of

an inch in a second, by increasing the speed sufficiently and giving

the wings an upward inclination, the air-ship instead of falling might

actually rise. And this, as we shall see presently, is just what the

flying-machines of Sir Hiram Maxim and Professor Langley and of the

Wright brothers and their imitators did do.

LANGLEY'S EARLY EXPERIMENTS AND DISCOVERIES

It was while making an important series of experiments with aeroplanes

that Professor Langley made the discovery which has since been known

as "Langley's Law." In effect this law is that while it takes a

certain strain to sustain a properly disposed weight while stationary

in the air, to advance the weight rapidly takes _even less strain_

than when the weight is stationary. Thus, contrary to opinions held

until recently, and contrary to the rules for land vehicles and ships,

the strain of resistance of an aeroplane will diminish instead of

increasing with the increase of speed. Professor Langley proved this

remarkable fact with a most simple but ingenious device. It consisted

of an immense "whirling table," driven by an engine, so arranged that

the end of a revolving arm could be made to travel at any speed up

to seventy miles an hour. At the end of this arm, surfaces disposed

like wings were placed, and whirled through the two hundred feet

circumference, until they were supported like kites by the resistance

of the air.

A certain strain was, of course, necessary to support one of these

winglike structures when stationary in the air, but, curiously enough,

less strain was required when it was advanced rapidly. Thus a brass

plate of proper shape weighing one pound was suspended from a pull-out

spring scale, the arm of which was drawn out until it reached the

one-pound mark. When the whirling table was rotated with increasing

velocity the arm indicated less and less strain, finally indicating

only an ounce when the speed of a flying bird was reached. "The brass

plate seemed to float on the air," says Professor Langley, "and not

only this, but taking into consideration both the strain and the

velocity, it was found that absolutely less power was spent to make the

plate move fast than slow, a result which seemed very extraordinary,

since in all methods of land and water transport a high speed costs

much more power than a slow one for the same distance."

These experiments, which destroyed the calculations of Newton, long

held to be correct, showed that mechanical flight was at least

theoretically possible, indicating as it did that a weight of two

hundred pounds could be moved through the air at express-train

speed with the expenditure of only one horse-power of energy. Since

engines could be constructed weighing less than twenty pounds to the

horse-power, theoretically such an engine should support ten times its

own weight in horizontal flight in an absolute calm. As a matter of

fact there is no such thing as an absolute calm in nature, air-currents

being constantly stirring even on the calmest day, and this introduces

another element in attaining aerial flight that is an all-important

one. Indeed it has long been recognized that the mechanical power for

flight is not the only requisite for flying--there is, besides, the art

of handling that power.

EXPERIMENTS IN SOARING

Those who have watched soaring birds sail for hours on rigidly extended

wings will remember that while there is no flying movement, there are

certain shifts of the rigid body, either to offset some unexpected

gust of wind, or to produce movement in a desired direction. There

is an art of balancing here that has become instinctive in the bird

by long practice which could not be hoped for in the same degree in

a mechanical device, and which man could hope to acquire only by

practice. But in the nature of the case man has little chance to learn

this art of balancing in the air, and it is for this reason that the

many members of the balloonist school advocate the inflated bag in

place of the aeroplane. The argument advanced by them is that since

man has no chance naturally to acquire familiarity with balancing in

the air, the simplest and best way for him to acquire it is by making

balloon ascensions. When he has acquired sufficient skill he can

gradually reduce the lifting part of his flying-machine, or gas-bag,

gradually increasing the aeroplane or other means of propulsion and

lifting, until the balloon part of his device can be dispensed with

entirely.

In short, this argument of the balloon advocates is comparable to

two schools of swimming-teachers, one of whom advocates the use of

sustaining floats until the knack of swimming is acquired, the other

depending upon the use only of muscular movements and quickly acquired

skill. In this comparison the aviators have all the best of the

argument; for it is a common observation that persons who attempt to

learn to swim by the use of floats of any kind acquire that art slowly

if at all; while those who plunge in boldly, although they run more

risks, quickly learn the art that seems ridiculously easy when once

acquired.

[Illustration: LEARNING HOW TO FLY.

This gliding apparatus is not unlike that with which M. Chanute and

other early experimenters tested the qualities of air currents. The

apparatus here shown is being drawn by an automobile, so that its

action is virtually that of a kite. This picture was taken at Morris

Park, New York, in 1909. The descent was made too abruptly and the

aviator was seriously injured.]

The great German scientist, Helmholtz, after years of careful study,

finally reached the conclusion that man would never be able to fly

by his own power alone. But, as we have seen, Professor Langley had

shown that in these mysterious questions pertaining to flight even a

Newton could be wrong; and why not Helmholtz? Otto Lilienthal, also a

German, thought that his fellow-countryman _was_ wrong. For years

he had made a study of the flight of birds, and his studies had led

him to the same conclusions that have usually been reached by every

student of the subject, both before and since--that soaring flight,

without any flapping movement, is possible under certain conditions;

that curved surfaces can acquire a horizontal motion by the action of

the wind alone, "when their curvature bears a certain relation to their

superficies"--in short, a relation represented exactly by the wings of

birds.

It was not supposed by Lilienthal, or by any of the members of the

school of aviators, that simply by making a device that reproduced the

proportions and shape of a bird any person might mount and fly. But it

was believed that, given such a device, a man might learn to fly with

practice. Lilienthal, therefore, constructed a flying-machine with

correctly curved surfaces made of linen stretched over a light wooden

frame, the total area being about fourteen square yards, and the whole

machine weighing only about forty pounds. In the center was an aperture

where the operator was stationed, holding the frame in position by

his arms. Obviously, as no flapping motion in imitation of a bird's

wings was possible, some other means of giving the necessary impetus

for horizontal flight was necessary, and here again the study of birds

suggested a method.

It is a well-known fact that certain soaring birds cannot leave

the ground when once they have alighted, except by an initial run

to acquire the necessary speed; and every goose hunter is familiar

with the manner in which these birds run along the surface of water,

flapping their wings and skimming along some distance before they

acquire sufficient velocity to mount into the air. A description of a

similar action of an eagle in leaving the earth, written by a careful

observer a few years ago, has become classic. This huntsman had come

upon an eagle which had alighted upon the sandy banks of the Nile, and

had fired at it, thus stimulating the bird to its utmost energy in

getting into flight. Yet on examining the foot-marks made in the sand

it was found that, even under these circumstances, the bird had been

obliged to run "full twenty yards before he could raise himself from

the earth. The marks of his claws were traceable on the sandy soil,"

says the writer, "as, at first with firm and decided digs, he found his

way, but as he lightened his body and increased his speed with the aid

of his wings, the imprints of his talons gradually merged into long

scratches."

It is evident that if such a master of the art of flying as an eagle

must thus acquire initial velocity before flight is possible, a human

novice must do considerably more. The method that would naturally

suggest itself would be that of running down the slope of a hillside,

and Lilienthal adopted this method, beginning his flights by running

down the gentle slope of a hill against the wind, until the requisite

momentum was acquired. This was, indeed, a reversion to some of the

oldest types of flying-machines, but with this difference--that it was

the result of scientific study. The results attained proved that the

theory was not visionary--that scientists had not dreamed and studied

in vain. For, as little by little the experimenter gained experience,

he was able to soar farther and farther in his birdlike machine, in

one flight sailing a distance of twelve hundred feet. Under certain

favorable wind conditions he could sail from a hilltop without the

initial run, and at times he actually rose in the air to a point higher

than that from which he started.

As was to be expected in the very nature of the case, Lilienthal found

that part of the secret of success lay in maintaining his equilibrium

and in acquiring the faculty of doing this instinctively, as a bird

does. But he found, like the person learning to ride a bicycle, that

this was developed by repeated efforts. The action of the machine

itself was carefully studied, and various changes were made in his

apparatus from time to time as experience suggested them. Among other

things, feather-like sails, worked by a small motor, were attached to

the edge of the wings; and two smaller frames placed one above the

other were tried in place of one large frame. And still the operator

continued to make successful flights in all kinds of winds, sometimes

narrowly escaping disaster, but for three years always coming to

the ground safely. His confidence increased day by day, and as his

remarkable performances multiplied it seemed as if it would only be a

matter of time until he would be able to imitate the soaring bird and

sail almost as he pleased.

In writing of his experiences when, as it sometimes happened, he found

himself practically motionless in the air at a point higher than that

from which he started, he says: "I feel very certain that if I leaned a

little to one side, and so described a circle, and further partook of

the motion of the lifting air around me, I should sustain my position.

The wind itself tends to direct this motion; but then it must be

remembered that my chief object in the air is to overcome the tendency

of turning to the right or left, because I know that behind or under

me lies the hill from which I started, and with which I would come in

rough contact if I allowed myself to attempt this circle-sailing. I

have, however, made up my mind, by means of either stronger wind or by

flapping the wings, to get higher up and farther away from the hills,

so that sailing round in circles, I can follow the strong, uplifting

current, and have sufficient air-space under and around me to complete

with safety a circle, and lastly to come up against the wind again to

land."

Before he was ready to make this attempt, however, Lilienthal was

killed by a fall caused by a treacherous gust of wind which tilted his

machine beyond his control and hurled him to the ground.

Again the expectant world of aerial navigators was thrown into

despondency by the happening of the long expected--expected, and yet

not expected; for Lilienthal had made so many daring flights under

so many trying conditions, always managing to alight safely, that a

feeling of confidence had succeeded that of distrust. It was almost

like a bolt from a clear sky, therefore, when the news was flashed

around the world that Lilienthal was no more. But science has never yet

been daunted by the fear of death. Like a well-formed battle-line in

which the place of the fallen is always quickly filled, there is always

a warrior-scientist ready to sacrifice anything for the cause. And so,

although Lilienthal was gone, the work he had carried so far toward

success was continued by others, Chanute and Hering, the American

"soaring men," and later eclipsed by the Wright brothers, who were

finally to solve the problem.

THE FLYING MACHINES OF MAXIM AND LANGLEY

At the same time that Lilienthal was making his initial experiments,

another champion of the same school of aviators was achieving equally

successful results along somewhat different, and yet on the whole,

similar lines. Sir Hiram Maxim, the inventor of so many destructive

types of guns, was devoting much time and energy to the construction

of a flying-machine. His apparatus was of the aeroplane type, but

unlike that of Lilienthal, Chanute, or Hering, was to be propelled by

steam-driven screw-propellers. Nor was the apparatus he proposed to

make a diminutive affair weighing a few pounds and capable of lifting

only the weight of a man. His huge machine weighed in the neighborhood

of four tons and carried a steam-engine that developed some three

hundred and sixty horse-power in the screws. It was two hundred feet

in width, and mounted on a car track, along which it was to be run to

acquire the necessary initial velocity before mounting into the air.

On July 31, 1894, this huge machine started on a trial spin, carrying

a crew of three persons, besides fuel and water for the boilers. When

a speed of thirty-six miles an hour on the track had been acquired,

the apparatus lifted itself in the air, and sailed for some distance,

a maximum flight of over three hundred feet finally being made. This

experiment demonstrated several important things--in fact, solved

"three out of five divisions of the problem of flight," as Lord Kelvin

declared. It demonstrated that a flying-machine carrying its own

propelling power could be made powerful and light enough to lift itself

in the air; that an aeroplane will lift much more than a balloon of

equal weight; and that a well-made screw-propeller will grip the air

sufficiently to propel a machine at a high rate of speed.

Since the two remaining divisions of the five concerned in the problem

of flight had been already solved by Lilienthal, it seemed that it only

remained for some scientist to combine this complete knowledge in the

proper way to produce a practical flying-machine--one that would fly

through the air, and continue to fly until the power was exhausted. It

was not a startling announcement to the scientific world, therefore,

when about three years later the news was flashed that Prof. S. P.

Langley had produced such an apparatus.

[Illustration: FLYING MACHINES OF THE MONOPLANE TYPE.

Upper figure, the aeroplane of M. Robert Esnault-Pelterie. Middle

figure, the aeroplane of M. Blériot. Lower figure, the Vuia aeroplane,

a bat-like machine of freakish structure which had no large measure of

success. A modification of the boat-like machine shown in the upper

figure gained celebrity through its use by M. Latham in the first

attempt (in July, 1909) to fly across the English Channel. M. Blériot's

aeroplane as finally developed became a very successful flying machine.

With its aid M. Blériot was first to accomplish the feat of flying

across the English Channel (from Calais to Dover in about 23 minutes)

on the morning of July 25th, 1909. These pictures are reproduced from

the London Graphic of January 25th, 1908.]

Professor Langley described this really wonderful machine, which he

called the "aerodrome," as follows:

"In the completed form there are two pairs of wings, each slightly

curved, each attached to a long steel rod which supports them both, and

from which depends the body of the machine, in which are the boilers,

the engines, the machinery, and the propeller wheels, these latter

being not in the position of an ocean steamer, but more nearly

amidships. They are made sometimes of wood, sometimes of steel and

canvas, and are between three and four feet in diameter.

"The hull itself is formed of steel tubing; the front portion is closed

by a sheathing of metal which hides from view the fire-grate and

apparatus for heating, but allows us to see a little of the coils of

the boiler and all of the relatively large smokestack in which it ends.

There is a conical vessel in front which is simply an empty float,

whose use is to keep the whole from sinking if it should fall in the

water.

"This boiler supplies steam for an engine of between one and one-half

horse-power, and, with its fire-grate, weighs a little over five

pounds. This weight is exclusive of that of the engine, which weighs,

with all its moving parts, but twenty-six ounces. Its duty is to drive

the propeller wheels, which it does at rates varying from 800 to 1,200,

or even more, turns a minute, the highest number being reached when the

whole is speeding freely ahead.

"The rudder is of a shape very unlike that of a ship, for it is adapted

both for vertical and horizontal steering. The width of the wings from

tip to tip is between twelve and thirteen feet, and the length of the

whole about sixteen feet. The weight is nearly thirty pounds, of which

about one-fourth is contained in the machinery. The engine and boilers

are constructed with an almost single eye to economy of weight, not

of force, and are very wasteful of steam, of which they spend their

own weight in five minutes. This steam might all be recondensed and

the water re-used by proper condensing apparatus, but this cannot be

easily introduced in so small a scale of construction. With it the time

of flight might be hours instead of minutes, but without it the flight

(of the present aerodrome) is limited to about five minutes, though in

that time, as will be seen presently, it can go some miles; but owing

to the danger of its leaving the surface of the water for that of the

land, and wrecking itself on shore, the time of flight is limited

designedly to less than two minutes."

When this flying-machine was put to the actual test its performance

justified the most sanguine expectations; it actually flew as no other

machine had ever flown before. A number of men of science watched

this remarkable performance, among others Alexander Graham Bell,

the inventor of the telephone, who reported it to the Institute of

France. "Through the courtesy of Mr. S. P. Langley, Secretary of the

Smithsonian Institution, I have had on various occasions the pleasure

of witnessing his experiments with aerodromes," wrote Dr. Bell, "and

especially the remarkable success attained by him in his experiments

made on the Potomac River on Wednesday, May 6th [which led me to urge

him to make public some of these results].

"On the occasion referred to, the aerodrome, at a given signal, started

from a platform about twenty feet above the water, and rose at first

directly in the face of the wind, moving at all times with remarkable

steadiness, and subsequently swinging around in large curves of,

perhaps, a hundred yards in diameter, and continually ascending until

its steam was exhausted, when at a lapse of about a minute and a half,

and at a height which I judged to be between eighty and one hundred

feet in the air, the wheels ceased turning, and the machine, deprived

of the aid of propellers, to my surprise did not fall, but settled down

so softly and gently that it touched the water without the least shock,

and was in fact immediately ready for another trial."

To most persons, even to the cautious and scientific inventor himself,

the performance of this, and a second aerodrome which flew about

three-quarters of a mile, seemed to show that the secret of aerial

navigation was all but fathomed. "The world, indeed, will be supine,"

Langley wrote a short time after the success of his flying-machine, "if

it does not realize that a new possibility has come to it, and that

the great universal highway overhead is soon to be opened." What could

be plainer? A machine of a certain construction, weighing some thirty

pounds, and carrying at that some excess of weight, had been able to

fly a relatively long distance. What easier than to construct a machine

on precisely similar lines only ten, a hundred, a thousand times

larger, until it would carry persons and cargo, and fly across an ocean

or a continent?

Professor Langley himself, as was most fitting, undertook the

construction of such a man-carrying air-ship. And it was during this

undertaking that he made the momentous discovery that seemed to

oppose a question mark to the possibility of flight by the aeroplane

principle. This discovery was an "unyielding mathematical law that

the weight of such a machine increases as the cube of its dimensions,

whereas the wing surface increases as the square." In other words, as

the machine is made larger, the size of the wings must be increased

in an alarmingly disproportionate ratio. And the best that Professor

Langley's man-carrying flying-machine could do, after the inventor had

expended the limit of his ingenuity, was to dive into the waters of

Chesapeake Bay, instead of soaring through the air as its prototype,

the aerodrome, had done.

THE IMPOSSIBLE ACCOMPLISHED

The plunge of Langley's aerodrome downward into the water instead of

upward through space as had been confidently expected, carried with

it the hopes of a great number of hitherto enthusiasts, who were now

inclined to believe that the practical conquest of the air was almost

as far beyond our reach as it had been beyond that of all preceding

generations. Learned scientists were able to prove to their own

satisfaction, by long columns of figures and elaborate mathematical

calculations, that the air is unconquerable.

[Illustration: THE WRIGHT AEROPLANE.

The aeroplane is here shown at rest, facing the right. This is the

original type of bi-plane flying machines, of which all the others are

only modifications. The starting-rail along which the machine glides

while acquiring momentum is seen at the right; the rope connecting

it with the starting derrick, at the left. The sledge-like runners,

intended to break the shock of alighting, are plainly shown. The

parallel planes of canvas at the right are horizontal rudders to direct

the machine upward or downward. The vertical planes at the left are

active rudders to direct the machine laterally. The two paddle-like

structures at the back of the machine are the wooden propellers,

actuated (at a rate of from 1000 to 1400 revolutions per minute) by

an oil motor. With a machine of this type the Wright brothers, of

Dayton, Ohio, were the first to demonstrate the feasibility of aerial

navigation with a heavier-than-air machine; and world-famous flights

were made by Mr. Orville Wright at Washington and by Mr. Wilbur Wright

in France in the summer of 1908.]

But even as they labored and promulgated these conclusions, two

unknown men in a little Ohio town, discarding all accepted theoretical

calculations, and combining with their newly created tables of figures

a rare quality of practical application and unswerving courage, had

accomplished the impossible. Wilbur and Orville Wright--two names

that must always be linked with those of Fulton and Stephenson, only

possibly on a higher plane as conquerors of a more subtle element--were

at that very time making flights in all directions at will through the

air in their practical flying-machine. While others caviled and

doubted, these two modest inventors worked and accomplished; until

presently they were able to put in evidence a mechanism that may

perhaps without exaggeration be regarded as the harbinger of a new era

of civilization.

The interest of these two brothers in the fascinating field of air

navigation was first excited when, as boys, their father, a clergyman,

brought home for their amusement the little toy known to scientists

as a "hélicoptère," which, actuated by twisted rubbers that drive

tiny paper screws in opposite directions, actually rises and flutters

through the air. "A toy so delicate lasted only a short time in

the hands of small boys, but its memory was abiding" the inventors

themselves have tersely said. So abiding, indeed, that a few years

later they began making similar "bats," as they had dubbed the machines.

Soon they discovered that the larger the machine they made the less it

flew, and in pondering this fact they gradually evolved for themselves

the theory which is now known as Langley's unyielding mathematical

law, referred to a few pages back. The problem of human flight had not

been considered by them at this time, and it was not until the news of

Lilienthal's death startled the world that they entered the field of

invention in earnest. Then they began constructing gliding machines,

modifications of those of Lilienthal and Chanute, and began making long

flights, studying defects and overcoming adverse conditions as they

presented themselves.

By 1901, they had surpassed the performances of all predecessors,

yet, as they tell us, "we saw that the calculations upon which all

flying-machines had been based were unreliable, and that all were

simply groping in the dark. Having set out with absolute faith in the

existing scientific data, we were driven to doubt one thing after

another, till finally, after two years of experiment, we cast it all

aside, and decided to rely entirely upon our own investigations.

Truth and error were everywhere so intimately mixed as to be

indistinguishable. Nevertheless, the time expended in preliminary

study of books was not misspent, for they gave us a good general

understanding of the subject, and enabled us at the outset to avoid

effort in many directions in which results would have been hopeless."

From mere gliding machines without self-contained power the brothers

progressed through the various stages of achievement until in the

fall of 1903 they had created the type of flying-machine now made so

familiar to everyone through the pictorial publications. Incidentally

they had invented and constructed their own gasoline motor for

furnishing the power--an accomplishment of no mean importance in

itself. On December 17th, 1903, in the presence of a small company of

witnesses who had braved the cold, the Wright machine, carrying one

of the brothers, made a short but successful flight--the first ever

accomplished in which a machine carrying a passenger had raised itself

by its own power, sailed a certain distance in free flight, yet subject

to guidance, and landed itself and its passenger safely. Mr. Hiram

Maxim's machine had, indeed, lifted itself and its passengers, but it

sailed unguided through the air, and it could in no sense be said to

have made a flight comparable to that of a bird or a bat. The Wright

machine, on the other hand, progressed through the air under guidance

of its passenger, rising or settling, or turning to right or left as he

wished. Its progress constituted, in other words, a veritable flight.

Yet the problem of perfectly controlled flight under all ordinary

conditions was by no means completely mastered. The principle was

correct, but there were endless details to be worked out. The

embodiment of these is the Wright flying-machine of the present time.

In the Wright aeroplane the lifting power is obtained by two parallel

horizontal planes of canvas stretched over retaining-frames, placed

with their long diameters transversely to the direction of flight, as

in the case of the wings of a bird. At a little distance, in front of

these, are placed two horizontal parallel rudders, and at the back two

parallel vertical rudders. The machine is mounted on huge skids, which

resemble giant sled-runners in shape, but lighter and more flexible,

and is driven by two wooden-bladed propellers not unlike some of the

types of ship-propellers. For stability in flight under all kinds of

atmospheric conditions this machine has shown itself to be a true

flying-machine, capable of navigating the air in any direction at

the will of the operator, and remaining in flight a length of time

dependent entirely upon the amount of fuel carried.

The stability of this machine, particularly in a transverse direction,

has proved far greater than that of any of its predecessors or

contemporaries. The two horizontal rudder-planes mounted in front

maintain the fore-and-aft stability; while keeping the machine on an

even keel is accomplished by varying the angle of incidence by warping

the two main planes,--this being, indeed, a vitally important feature

of the mechanism. In this manner a greater lift on the low side and a

diminished lift on the high side is obtained, this being maintained

manually, as is the fore-and-aft stability. Since the warping of the

wings of the machine would tend to deflect it from its course, the

apparatus is so arranged that a single lever controls the flexible

portion of the wings and the vertical rudder, the motion of the latter

counteracting the disturbing influence that would otherwise result

from the twisting of the wing-tips. The discovery of this combination

gave the finishing touches to the aeroplane, and made it a manageable

mechanism. In other words, it made the flying machine a machine in

which man could fly.

[Illustration: MR. WILBUR WRIGHT PREPARING TO ASCEND IN HIS AEROPLANE

WITH HIS PUPIL M. CASSANDIER.]

This mechanism was patented in 1906, and the patent office

specifications then became accessible to other experimenters. The

French scientific workers had for some time recognized the success

of the Wright brothers' efforts, even when most Americans were

still skeptical. Now that the manner in which this success had been

obtained was disclosed, numerous experimenters began copying the

Wright brothers' successful machine, making sundry modifications,

while still adhering to the main principles through which success had

been obtained. The first of these experimenters to win conspicuous

success was Mr. Henry Farman, an Englishman residing in Paris, who on

the 13th of January, 1908, aroused the enthusiasm of the entire world,

and won a £2000 prize, by flying in a heavier-than-air machine in a

prescribed circle, covering about sixteen hundred yards, and alighting

at the starting-point.

This was more than four years after the Wright brothers had made far

more remarkable flights, to which few persons had paid any attention,

and of which most people had never heard. But in the autumn of the

same year Orville Wright in America, and Wilbur Wright in France began

a series of public flights which demonstrated for all time that the

air at last had been conquered, and that they were the unquestionable

conquerors. Orville, at Fort Myer, near Washington, on September

12th, electrified the world by flying continuously around a circular

course for an hour and fifteen minutes. This was the most conclusive

performance yet accomplished and set at rest all doubts as to the

possibility of mechanical flight. For no one could doubt that a machine

which could maintain itself in the air by its own power for more than

an hour was truly a flying-machine in the most exacting sense of the

term.

A few days after this performance an accident to the propeller of

this machine wrecked it, the resulting fall breaking the leg of the

inventor, and killing his companion, Lieutenant Selfridge of the United

States Army.

Almost simultaneously Wilbur Wright began a series of flights at

Le Mans, France, which demonstrated still more conclusively that

erstwhile earth-bound man had really learned to fly. His longest flight

lasted for two hours, twenty minutes, and twenty-three seconds; while

by flying over captive balloons at an altitude of three hundred and

sixty feet, he demonstrated that the mere matter of altitude offered no

obstacle.

From this time forward the number of aeronauts increased day by day,

and new records were made in bewildering confusion. Only a few of the

more spectacular of these need be referred to. On July 19, 1909, Hubert

Latham attempted a flight across the English Channel, but his motor

failed him and his machine plunged into the water, from which, however,

he was rescued, having suffered no injury. On July 25th, Louis Blériot

made a similar attempt with better results. Starting from the cliffs

near Calais he made the passage without mishap and landed near Dover.

[Illustration: THE FARMAN AEROPLANE.

This is the machine with which Mr. Farman, an Englishman living in

France, won the Deutsch prize in the early spring of 1908. This

performance was notable as being the most important public flight

hitherto made by a heavier-than-air machine. The Wright brothers of

Dayton, Ohio, had made numerous flights of far greater length, but the

general public was not aware of that fact and for a time Mr. Farman was

popularly regarded as the foremost of aviators. His best performances

were, however, eclipsed by the public flights of the Wright brothers a

few months later.]

There was of course no particular difficulty involved in the flight

across the Channel; but its obvious dangers, together with the

suggestion as to the new possibilities of the use of the airship in war

time,--the virtual elimination of that all-important barrier of water

that had proved so effective against England's foes in the past,--gave

to Blériot's flight a popular interest not exceeded by any preceding

achievement even of the Wright brothers. We may add that Blériot's

feat was presently duplicated by another Frenchman, Count Jacques de

Lesseps by name, who crossed the Channel in an aeroplane in May, 1910;

and excelled by the Hon. Charles S. Rolls, an Englishman, who on June

2nd, 1910, made a still more remarkable flight, in which he crossed

the Channel, starting from the cliffs near Dover, and after circling

over French soil without landing, returned to his starting-place. The

aeroplanes used by the two Frenchmen were of the monoplane type; that

used by Mr. Rolls was a Wright bi-plane.

Just at the time when the first successful cross-Channel flight was

made, the attention of aviators was focussed on the flights being made

near Washington by Mr. Orville Wright in the attempt to fulfill the

Government tests which had been so tragically interrupted the year

before. On July 27th, 1909, Mr. Wright successfully met the conditions

of the endurance test, by flying more than an hour carrying as a

passenger Lieutenant Frank P. Lahm. Three days later a more spectacular

flight, to a distance of five miles across country and return, over

tree-tops, hills, and valleys, with a passenger (Lieutenant Foulois),

was accomplished without mishap. This was in many respects the most

important flight, as suggesting the possible practical utility of the

aeroplane, that had hitherto been made.

Later in the same year Mr. Orville Wright went abroad with his

aeroplane and made a large number of flights at Berlin, demonstrating

to the German people the points of superiority of the aeroplane as

against the gigantic dirigible balloons to which that nation had

heretofore paid chief attention. Mr. Wilbur Wright meantime remained in

America to give flights about New York Harbor during the Hudson-Fulton

Centenary Celebration. On October 4th (1909), he made a sensational

flight up the Hudson from Governor's Island, circling about above the

warships anchored in the river in the neighborhood of Grant's Tomb, and

returning to land at his starting-point. What would probably have been

a still more spectacular flight was prevented by an accident to Mr.

Wright's motor just as he was about to start on the afternoon of the

same day.

Another flight that aroused great popular interest and enthusiasm was

made by the Frenchman Louis Paulhan in competition for a prize of

ten thousand pounds offered by the Daily Mail of London for a flight

from London to Manchester. Paulhan left London at 5:20 on the evening

of April 28, 1910. He descended at Litchfield but renewed his flight

early next morning, arriving at Manchester at 8:10. He had covered the

distance of 186 miles with a single stop, his actual flying time being

four hours and eleven minutes, or an average rate of 44.3 miles an

hour. In this flight M. Paulhan had for his only competitor Mr. White,

an Englishman, who made a daring flight but did not cover the entire

distance.

Paulhan had previously been known as one of the most daring of

aviators. At Los Angeles, California, on January 13, 1910, he rose to a

height of about 4,163 feet, establishing a record for altitude. He had

also made thrilling cross-country flights on the occasion of the Los

Angeles meet, as well as in France. Paulhan's record flights were made

in a Farman bi-plane.

[Illustration: THE MONOPLANES OF BLÉRIOT AND LATHAM.

The upper figure is that of Blériot launched for his flight across the

English Channel, on July 25th, 1909. The lower shows Latham starting in

an attempt to cross the Channel, which barely failed of success through

fault of the motor.]

The spectacular flight from London to Manchester was matched soon

after by Mr. Glenn H. Curtiss' flight from Albany to New York, which

took place May 29, 1910. Mr. Curtiss had already achieved fame as an

aviator, having won the chief speed contest in the International

Aviation Meet held at Rheims in August, 1909. He used a bi-plane of

his own construction, differing but little in design from the Wright

machine, but of very small size, and propelled by an eight-cylinder

motor, also made by Mr. Curtiss himself. The start from Albany was

made at three minutes after seven o'clock and the aviator arrived at

Governor's Island, New York Harbor, at twelve o'clock, having stopped

twice on the way to rest and take on fuel. The first stop was made

near Poughkeepsie, the second on the heights near the Hudson, within

the bounds of New York City. The distance covered 142½ miles; the

actual time of flight, 2 hours and 54 minutes,--an average speed

of about fifty miles an hour. Parts of the flight were made at a

good deal better speed. The first part of the journey from Albany

to Poughkeepsie, a distance of 74¼ miles, was covered in 1 hour 23

minutes, or at a rate of more than 53.68 miles an hour. The minimum

speed at which Mr. Curtiss' bi-plane could be maintained in the

air is about 40 miles an hour, the supporting surface of its main

plane comprising only 236 square feet, and the weight of the machine

complete, including aviator, fuel, and oil, being 950 pounds. The

machine uses a single propeller, 7 feet in diameter, making 1,100

revolutions per minute, and giving a pull, when the machine is held

stationary on the ground, of over 300 lbs. The engine used is an

eight-cylinder motor of 50 horse-power.

A flight in some respects even more interesting than that of Mr.

Curtiss was accomplished in France on the ninth of June, 1910, by

Lieutenant Feguant and Captain Marconnet, officers of the French army,

on a Farman bi-plane. "Starting from Chalons at 4:40 A. M.," says the

_Scientific American_, "the officers flew 176 kilometers (109¼ miles)

across country to the artillery park at Vincennes, which was reached at

7:10. This flight of two and one-half hours' duration was accomplished

at a speed of 43¾ miles per hour. Captain Marconnet was able to take

photographs and make sketches that would have been of great strategic

interest in time of war. This is the first practical demonstration of

the aeroplane for scouting purposes, in addition to its being a new

world's record for cross-country flying with two men in the machine.

Another French aviator, Labouchère, flew for ten minutes with two

passengers at Mourmelon on the same day."

[Illustration: A BRITISH AEROPLANE.

This apparatus was built and is operated by Colonel Cody of the British

Army. It has made flights of a mile or more. With minor modifications

it is, like all bi-plane flying machines hitherto constructed, of the

Wright aeroplane type.]

A record flight of yet another character was accomplished in America

by Charles K. Hamilton, a disciple of Curtiss, who, flying under

the auspices of the New York _Times_ and the Philadelphia _Public

Ledger_, attempted successfully a round-trip flight from New York to

Philadelphia on June 14, 1910. The aviator left Governor's Island at

7:36 A. M. and landed at Philadelphia at 9:26 A. M., having covered the

86 miles at an average speed of 46.92 miles an hour. After delivering

messages from the Governor of New York, and the Mayor of New York City,

Mr. Hamilton took wing at 11:33 for the return voyage. A difficulty

with his motor made it necessary for him to descend at South Amboy,

after covering 68 miles in 1 hour and 21 minutes. An injury to the

propeller necessitated a delay of several hours, but the aviator was

enabled to re-ascend at 6:17 and to land at Governor's Island at 6:40,

the return journey having been accomplished at an average hourly speed

of 51.36 miles.

The machine used by Mr. Hamilton is a Curtiss bi-plane, which in most

respects follows closely the model of the original Wright aeroplane,

but in which the function of the warping wings is fulfilled by two

small wings, or ailerons, adjusted at each side between the larger

planes. These ailerons, being deflected in opposite directions

simultaneously, meet any tendency of the machine to tip unduly.

Whether or not this method of maintaining lateral stability is the

same in principle as the Wright method of warping the large planes

themselves, is a question at issue between the inventors. From the

purely scientific standpoint it would seem that one method is merely a

modification of the other, which, however ingenious in its application,

introduces no new principle.

On the same day on which Mr. Hamilton's inter-urban flight took

place, a new record for altitude was made at Indianapolis by Mr. W.

H. Brookins, a pupil of the Wrights, who rose in the Wright bi-plane

to a height of 4,384 feet. The height was calculated by President

Lambert of the St. Louis Aero Club, with the aid of a sextant. Earlier

in the same day Mr. Brookins had risen about 2,000 feet. It becomes

increasingly difficult for an aeroplane to rise to great heights owing

to rarefaction of the upper atmosphere, but the flights of Paulhan

and Brookins, as well as various unmeasured altitudes attained in

cross-country flights, show that the aeroplane as at present equipped

may be depended upon to rise well toward the mile limit.

These are but a few of the interesting flights made within a brief

period after the Wright brothers' first successful demonstrations.

The number of the aviators who so quickly entered the field, and the

prominence given by the press to such feats as those of Blériot,

Paulhan, and Curtiss, have tended to distract attention from the

original inventors, and to produce some confusion in the popular mind

as to the exact share the various aviators have taken in the conquest

of the air. The facts, however, are quite clear and unequivocal. At

the time when the Wright brothers made their first successful flights,

comparatively few people in the world believed that anyone would ever

be able to propel himself through the air with safety or certainty in a

heavier-than-air apparatus.

The Wright brothers solved the problem after years of patient effort,

and solved it effectively and conclusively. They profited of course by

the efforts of predecessors, but they were the inventors of the airship

in a far fuller sense than, for example, Fulton was the inventor of the

steamboat, or Stephenson of the locomotive, or Morse of the telegraph.

To their success, and to that alone, must be ascribed the fact that

many scores of men in various parts of the world are now able to fly

in aeroplanes. Slight modifications of type mark various of these

aeroplanes, but no radical departure in principle.

[Illustration: Mr. Wilbur Wright flying over New York Harbor, October

4, 1909.]

In time, no doubt, flying-machines of quite different types will be

invented. Quite possibly the machines of the Wright model will

become altogether obsolete. But this can have no possible effect upon

the position that the Wright brothers themselves must always hold in

the history of scientific progress. The men who fly from New York

to San Francisco, or from New York to London, will be carrying out

the work of the Dayton pioneers; and no future accomplishment of the

heavier-than-air machine can possibly rank in historical importance

with that first flight in the presence of witnesses made December 17,

1903. Then and there it was successfully demonstrated that the last

difficulty, so far as joining theory and practice was concerned, had

been mastered. Potentially, from that moment, the conquest of the air

was complete; and the names of the conquerors as all the world knows,

and as throughout the future all must remember, are Wilbur and Orville

Wright.

APPENDIX

REFERENCE LIST AND NOTES

CHAPTER II

THE HIGHWAY OF THE WATERS

(pp. 77-79). The _Great Eastern_. The quotation is from _Ancient and

Modern Ships_, by Sir George C. V. Holmes, K.C.V.O., London, 1906.

CHAPTER III

SUBMARINE VESSELS

(pp. 95, 98). The first submarine. As stated in the text the quotation

is from a letter written to Thomas Jefferson by David Bushnell, and

published in the _Transactions of the American Philosophical Society_

in 1789.

(pp. 104-105). A successful diving boat. The quotation is from _The

Naval History of the Civil War_, by Admiral Porter.

CHAPTER IV

THE STEAM LOCOMOTIVE

(pp. 127, 128). George Stephenson's locomotive of 1825. The quotation

is from _The History of the First Locomotive in America_, by William H.

Brown, New York 1874.

CHAPTER VI

THE DEVELOPMENT OF ELECTRIC RAILWAYS

(pp. 179-181). Early experimental railways. The quotation is from the

article on "Street and Electric Railways," by Thomas Commerford Martin,

in the Special Report of the U. S. Census Office on Street and Electric

Railways, Washington, 1905.

CHAPTER IX

NAVIGATING THE AIR

(p. 247). Henson's studies of the flying-machine. The quotation is from

_Travels in Space_, by E. Seton Valentine and F. L. Tomlinson, New

York, 1902.

CHAPTER X

THE TRIUMPH OF THE AEROPLANE

(p. 275). How the air supports a heavier-than-air mechanism. The

quotation is from an article on "The Flying Machine," by Professor S.

P. Langley, in _McClure's Magazine_ for June, 1897.

(p. 284). Langley's aerodrome. The description is from Professor

Langley's own account in _McClure's Magazine_, above cited.

(pp. 289, 290). Experiments of the Wright brothers. The quotation is

from an article on "The Wright Brothers' Aeroplane," by Orville and

Wilbur Wright, in _The Century Magazine_ for September, 1908.

(p. 298). Cross-country Bight by French officers. The quotation is from

the _Scientific American_ of June 18, 1910. This periodical has shown

great interest in the new science of aeronautics, and was the first to

offer a trophy for long-distance flying--a trophy that was won for the

years 1908 and 1909 by Mr. Glenn H. Curtiss. The Wright brothers have

declined to compete for prizes; otherwise "records" for cross-country

flying and the like would doubtless have advanced even more rapidly

than has been the case.

Transcriber's Notes:

Punctuation and spelling were made consistent when a predominant

preference was found in this book; otherwise they were not changed.

Simple typographical errors were corrected; occasional unbalanced

quotation marks retained.

Ambiguous hyphens at the ends of lines were retained.

Text uses both "aerial" and "aërial".

The references to Figs. 1 and 2 used subscripts. They are represented

here as simple numbers, e.g., R1.

Page 262: "representing six thousand words" should be "representing six

hundred thousand words".