I have told in the first "Boys' Book of Inventions" of Guglielmo Marconi's early experiments. That was a chapter of uncertain beginnings, of great hopes, of prophecy. This is the sequel, a chapter of achievement and success. What was only a scientific and inventive novelty a few years ago has become a great practical enterprise, giving promise of changing the whole world of men, drawing nations more closely together, making us near neighbours to the English and the Germans and the French--in short, shrinking our earth. There may come a time when we will think no more of sending a Marconigram, or an etheragram, or whatever is to be the name of the message by wireless telegraphy, to an acquaintance in England than we now think of calling up our neighbour on the telephone. Every one will recall the astonishment that swept over the country in December, 1901, when there came the first meagre reports of Marconi's success in telegraphing across the Atlantic Ocean between England and Newfoundland. At first few would believe the reports, but when Thomas A. Edison, Graham Bell, and other great inventors and scientists had expressed their confidence in Marconi's achievement, the whole country, was ready to hail the young inventor with honours. And his successes since those December days have been so pronounced--for he had now sent messages both ways across the Atlantic and at much greater distances--have more than borne out the promise then made. Wireless telegrams can now be sent directly from the shore of Massachusetts to England, and ocean-going ships are being rapidly equipped with the Marconi apparatus so that they can keep in direct communication with both continents during every day of the voyage. On some of the great ships a little newspaper is published, giving the world's news as received from day to day. It was the good fortune of the writer to arrive in St. John's, Newfoundland, during Mr. Marconi's experiments in December, 1901, only a short time after the famous first message across the Atlantic had been received. Three months later it was also the writer's privilege to visit the Marconi station at Poldhu, in Cornwall, England, from which the message had been sent, Mr. Marconi being then planning his greater work of placing his invention on a practical basis so that his company could enter the field of commercial telegraphy. It was the writer's fortune to have many talks with Mr. Marconi, both in America and in England, to see him at his experiments, and to write some of the earliest accounts of his successes. The story here told is the result of these talks.