Edison believes that his early struggles, severe as they were, did him a great deal of good and stiffened his backbone. He absolutely refuses to believe that even his deafness has been a handicap. About this trouble he once said: “This deafness has been a great advantage to me in many ways. When in a telegraph office I could hear only the instrument directly on the table at which I sat, and unlike the other operators I was not bothered by the other instruments.... Again, my nerves have been preserved intact. Broadway is as quiet to me as a country village is to a person with normal hearing.” No man living has a greater list of inventions to his credit than Edison. Even to give a list of them would occupy several pages of a book. While one naturally thinks of such outstanding inventions as the phonograph yet he has made scores of other important discoveries all of a useful character. He believes that his success is chiefly due to his ability to concentrate. When some one asked him what he considered was the secret of his success he replied: “The ability to apply physical and mental energies to one problem incessantly without growing weary.” He has often worked twenty hours a day for days at a time and has actually toiled at one problem for sixty consecutive hours. Concentration may be one of the principal reasons for his success, but it does not account for everything. Edison, as a boy, faced difficulties and utterly refused to be discouraged. He made them stepping-stones to success. Any man who can believe that even deafness has been a help to him surely has the quality of courage which makes heroes. CHAPTER X THE UNLETTERED BOY WHO BECAME A TREE DOCTOR One day, more than seventy years ago, in Somersetshire, England, a four year-old boy was watching his father plant potatoes. The man was a poor tenant farmer and the little boy, whose name was John Davey, never lost a chance of seeing his father work. Young though he was, it seemed to John Davey that the most wonderful things in the world were the things which grew in gardens and fields. Flowers, vegetables or grain; how could these things spring out of tiny seeds that were sown in the ground? That was what puzzled the little fellow. Suddenly he turned to his father and asked if he might plant a potato. His father smiled and gave him one, telling him to cut it in two, and explaining how it should be put into the ground. John was very much excited, but he was much too little to handle the shovel, so his father got him an iron spoon. John cut the potato in two, planted it in the ground, and covered it with earth.