In 1874 I discovered a method of transmitting musical tones telegraphically, and the thing that set my mind in that direction was a domestic incident. It is a curious fact that most inventions have their beginnings in some incident or observation that comes within the experience of some one who is able to see and interpret the meaning of such incidents or observations. I do not mean to say that inventions are usually the result of a happy thought, or accident; the germ may be, but the germ has to have the right kind of soil to take root in and the right kind of culture afterward. It is a rare thing that an invention, either of commercial or scientific importance, ever comes to perfection without hard work--midnight oil and daylight toil; and it is rarely, if ever, that a discovery or an invention based upon a discovery does not have, sooner or later, a practical use, although we sometimes have to wait centuries to find it put. We had to wait forty-four years after the galvanic battery was discovered before it became a useful servant of man. It was fifty years or more after the discovery by Faraday of magneto-electricity before it found a useful application beyond that of a mere toy, but now it is one of the most useful servants we have, as shown in its wonderful development in electric lighting and electric railroads, to say nothing of its heating qualities and the useful purpose it serves in driving machinery. The interesting discoveries of Professor Crookes in passing a current of electricity through tubes of high vacua waited many years before they found a practical use in the X-ray, that promises to be of great service in medicine and surgery.