The story of James Watt's sensations when the driving-wheels of his first rude engine began to revolve will never be told; the visions of Robert Fulton, when he puffed up the Hudson, of the fleets of vessels that would follow the faint track of his little vessel, can never be put in print. It is the purpose of this book to give, in a measure, the adventurous side of invention. The trials and dangers of the builders of the submarine; the triumphant thrill of the inventor who hears for the first time the vibration of the long-distance message through the air; the daring and tension of the engineer who drives a locomotive at one hundred miles an hour. The wonder of the mechanic is lost in the marvel of the machine; the doer is overshadowed by the greatness of his achievement. These are true stories of adventure in invention. STORIES OF INVENTORS HOW GUGLIELMO MARCONI TELEGRAPHS WITHOUT WIRES A nineteen-year-old boy, just a quiet, unobtrusive young fellow, who talked little but thought much, saw in the discovery of an older scientist the means of producing a revolutionising invention by which nations could talk to nations without the use of wires or tangible connection, no matter how far apart they might be or by what they might be separated. The possibilities of Guglielmo (William) Marconi's invention are just beginning to be realised, and what it has already accomplished would seem too wonderful to be true if the people of these marvellous times were not almost surfeited with wonders. It is of the boy and man Marconi that this chapter will tell, and through him the story of his invention, for the personality, the talents, and the character of the inventor made wireless telegraphy possible. It was an article in an electrical journal describing the properties of the "Hertzian waves" that suggested to young Marconi the possibility of sending messages from one place to another without wires. Many men doubtless read the same article, but all except the young Italian lacked the training, the power of thought, and the imagination, first to foresee the great things that could be accomplished through this discovery, and then to study out the mechanical problem, and finally to steadfastly push the work through to practical usefulness. It would seem that Marconi was not the kind of boy to produce a revolutionising invention, for he was not in the least spectacular, but, on the contrary, almost shy, and lacking in the aggressive enthusiasm that is supposed to mark the successful inventor; quiet determination was a strong characteristic of the young Italian, and a studious habit which had much to do with the great results accomplished by him at so early an age.