electricity that would vary in intensity as the air varies in density during the utterance of speech sounds. I followed these directions and had the instrument ready for its trial the very next day. I rushed it, for Bell’s excitement and enthusiasm over the discovery had aroused mine again, which had been sadly dampened during those last few weeks by the meagre results of the harmonic experiments. I made every part of that first telephone myself, but I didn’t realize while I was working on it what a tremendously important piece of work I was doing. [Illustration: WHAT THE FIRST TELEPHONE LOOKED LIKE ALEXANDER GRAHAM BELL’S FIRST TELEPHONE] The First Telephone Line. “The two rooms in the attic were too near together for the test, as our voices would be heard through the air, so I ran a wire especially for the trial from one of the rooms in the attic down two flights to the third floor where Williams’ main shop was, ending it near my work bench at the back of the building. That was the first telephone line. You can well imagine that both our hearts were beating above the normal rate while we were getting ready for the trial of the new instrument that evening. I got more satisfaction from the experiment than Mr. Bell did, for shout my best I could not make him hear me, but I could hear his voice and almost catch the words. I rushed upstairs and told him what I had heard. It was enough to show him that he was on the right track, and before he left that night he gave me directions for several improvements in the telephones I was to have ready for the next trial.” Then followed many heart-breaking months of experimenting and it was not until the following March that the telephone was able to transmit a complete, intelligible sentence. [Illustration: TELEPHONE APPARATUS PATENTED IN 1876 BY PROF. BELL, PHOTOGRAPHED FROM THE ORIGINAL INSTRUMENTS IN THE PATENT OFFICE AT WASHINGTON] On February 14, 1876, Professor Bell filed at Washington his application for patents covering the telephone which he described as “an improvement in telegraphy” and on March 3, of the same year, the patent was allowed. That was the year of the Centennial Exposition at Philadelphia and Professor Bell had a working model of the telephone on exhibition. Tucked away in an obscure corner it had attracted but little attention, until on June 25th an incident occurred which had a tremendous effect in giving to the new invention just the sort of publicity it needed. Professor Bell himself describes the incident in the following interesting manner: “Mr. Hubbard and Mr. Saunders, who were financially interested in the telephone, wanted this instrument to be exhibited at the Centennial Exhibition. In those days--and I must say even up to the present time I am afraid to say it is true--I was not very much alive to commercial matters, not being a business man myself. I had a school for vocal physiology in Boston. I was right in the midst of examinations.