His son Alexander was born in Edinburgh in 1847 and was educated at the University of Edinburgh. He removed to London when he was twenty years of age and was for a time in the University there. Three years later he went to Canada with his father, and at the age of twenty-five took up his residence in the United States, and became professor of vocal physiology in Boston University. He had been in this country but three years when he made his great invention, and its complete success gave him immense wealth. Later he invented the "photophone," in which a vibratory beam of light is substituted for a wire in conveying speech. This instrument has attracted much attention but has not proved of practical use. Professor Bell is a member of various learned societies and has published many scientific papers. His present home is in Washington. Within ten years the art of telephoning has rapidly developed. This has stimulated inventions and brought into use a vast number of special contrivances for local and long-distance transmission. The principal inventors of these new contrivances are Bell, Berliner, Edison, Hughes, Dolbear, Gray, Blake, and Peirce. Nearly all of the telephone business of our country is carried on under licenses from the American Bell Telephone Company. The telephone lines at present in the United States would aggregate a distance of more than six hundred thousand miles, and there are more than half a million instruments in our country alone. The longest telephone line extends from Portland, Maine, via Boston, New York, and Chicago, to Milwaukee, a distance of more than thirteen hundred miles. [Illustration: ALEXANDER BELL USING A LONG-DISTANCE TELEPHONE.] Let us consider for a moment the wonders of this marvelous invention, as compared with another no less marvelous in its way. In 1867 Anson Burlingame was appointed by the Chinese Government special envoy to the United States and the great European governments, with power to frame treaties of friendship with those nations. This was an honor never before conferred on a foreigner. Mr. Burlingame accepted the appointment and, at the head of a large mission of distinguished Chinese officials, arrived in this country early in 1868, negotiated with our Government the "Burlingame Treaty," proceeded the same year to England, thence to France, the next year to Denmark, Sweden, Holland, and Prussia, and finally reached Russia early in 1870. He died in St. Petersburg after a few days' illness, on the 23d of February.