ticked off on each private instrument automatically, "Marconigraphed" from the editorial rooms; the sending and receiving of messages from moving trains or any other kind of a conveyance; the direction of a submarine craft from a safe-distance point, or the control of a submarine torpedo.

One is apt to grow dizzy if the imagination is allowed to run on too far—but why should not one friend talk to another though he be miles away, and to him alone, since his portable instrument is attuned to but one kind of vibration. It will be like having a separate language for each person, so that "friend communeth with friend, and a stranger intermeddleth not—" and which none but that one person can understand.

SANTOS-DUMONT AND HIS AIR-SHIP

There was a boy in far-away Brazil who played with his friends the game of "Pigeon Flies."

In this pastime the boy who is "it" calls out "pigeon flies," or "bat flies," and the others raise their fingers; but if he should call "fox flies," and one of his mates should raise his hand, that boy would have to pay a forfeit.

The Brazilian boy, however, insisted on raising his finger when the catchwords "man flies" were called, and firmly protested against paying a forfeit.

Alberto Santos-Dumont, even in those early days, was sure that if man did not fly then he would some day.

Many an imaginative boy with a mechanical turn of mind has dreamed and planned wonderful machines that would carry him triumphantly over the tree-tops, and when the tug of the kite-string has been felt has wished that it would pull him up in the air and carry him soaring among the clouds. Santos-Dumont was just such a boy, and he spent much time in setting miniature balloons afloat, and in launching tiny air-ships actuated by twisted rubber bands. But he never outgrew this interest in overhead sailing, and his dreams turned into practical working inventions that enabled him to do what never a mortal man had done before—that is, move about at will in the air.

Perhaps it was the clear blue sky of his native land, and the dense, almost impenetrable thickets below, as Santos-Dumont himself has suggested, that made him think how fine it would be to float in the air above the tangle, where neither rough ground nor wide streams could hinder. At any rate, the thought came into the boy's mind when he was very small, and it stuck there.

His father owned great plantations and many miles of railroad in Brazil, and the boy grew up in the atmosphere of ponderous machinery and puffing locomotives. By the time Santos-Dumont was ten years old he had learned enough about mechanics to control the engines of his father's railroads and handle the machinery in the factories. The boy had a natural bent for mechanics and mathematics, and possessed a cool courage that made him appear almost phlegmatic. Besides his inherited aptitude for mechanics, his father, who was an engineer of the Central School of Arts and Manufactures of Paris, gave him much useful instruction. Like Marconi, Santos-Dumont had many advantages, and also, like the inventor of wireless telegraphy, he had the high intelligence and determination to win success in spite of many discouragements. Like an explorer in a strange land, Santos-Dumont was a pioneer in his work, each trial being different from any other, though the means in themselves were familiar enough.

The boy Santos-Dumont dreamed air-ships, planned air-ships, and read about aerial navigation, until he was possessed with the idea that he must build an air-ship for himself.

He set his face toward France, the land of aerial navigation and the country where light motors had been most highly developed for automobiles. The same year, 1897, when he was twenty-four years old, he, with M. Machuron, made his first ascent in a spherical balloon, the only kind in existence at that time. He has described that first ascension with an enthusiasm that proclaims him a devotee of the science for all time.

His first ascension was full of incident: a storm was encountered; the clouds spread themselves between them and the map-like earth, so that nothing could be seen except the white, billowy masses of vapour shining in the sun; some difficulty was experienced in getting down, for the air currents were blowing upward and carried the balloon with them; the tree-tops finally caught them, but they escaped by throwing out ballast, and finally landed in an open place, and watched the dying balloon as it convulsively gasped out its last breath of escaping gas.

After a few trips with an experienced aeronaut, Santos-Dumont determined to go alone into the regions above the clouds. This was the first of a series of ascensions in his own balloon. It was made of very light silk, which he could pack in a valise and carry easily back to Paris from his landing point. In all kinds of weather this determined sky navigator went aloft; in wind, rain, and sunshine he studied the atmospheric conditions, air currents, and the action of his balloon.

The young Brazilian ascended thirty times in spherical balloons before he attempted any work on an elongated shape. He realised that many things must be learned before he could handle successfully the much more delicate and sensitive elongated gas-bag.

In general, Santos-Dumont worked on the theory of the dirigible balloon—that is, one that might be controlled and made to go in any direction desired, by means of a motor and propeller carried by a buoyant gas-bag. His plan was to build a balloon, cigar-shaped, of sufficient capacity to a little more than lift his machinery and himself, this extra lifting power to be balanced by ballast, so that the balloon and the weight it carried would practically equal the weight of air it displaced. The push of the revolving propeller would be depended upon to move the whole air-ship up or down or forward, just as the motion of a fish's fins and tail move it up, down, forward, or back, its weight being nearly the same as the water it displaces.

The theory seems so simple that it strikes one as strange that the problem of aerial navigation was not solved long ago. The story of Santos-Dumont's experiments, however, his adventures and his successes, will show that the problem was not so simple as it seemed.

Santos-Dumont was built to jockey a Pegasus or guide an air-ship, for he weighed but a hundred pounds when he made his first ascensions, and added very little live ballast as he grew older.

Weight, of course, was the great bugbear of every air-ship inventor, and the chief problem was to provide a motor light enough to furnish sufficient power for driving a balloon that had sufficient lifting capacity to support it and the aeronaut in the air. Steam-engines had been tried, but found too heavy for the power generated; electric motors had been tested, and proved entirely out of the question for the same reason.

Santos-Dumont has been very fortunate in this respect, his success, indeed, being largely due to the compact and powerful gasoline motors that have been developed for use on automobiles.

Even before the balloon for the first air-ship was ordered the young Brazilian experimented with his three-and-one-half horse-power gasoline motor in every possible way, adding to its power, and reducing its weight until he had cut it down to sixty-six pounds, or a little less than twenty pounds to a horse-power. Putting the little motor on a tricycle, he led the procession of powerful automobiles in the Paris-Amsterdam race for some distance, proving its power and speed. The