Fourteen-cylinder 100-horsepower Gnome motor. Used on many racing aeroplanes.] [Illustration: Courtesy of the _Scientific American_ Testing a Gnome motor on a gun carriage. So great is the power of the engine that the tongue of the heavy carriage is buried in the ground to hold it in place.] "Why can't we make a glider that would be a success?" the brothers asked each other. They were sure they could, and they got so excited in talking it over that it nearly brought back Orville's fever. When he got well they studied aeronautics with the greatest care, approaching the subject with all the thoroughness that later made their name a byword in aviation for care and deliberation. Neither of these two young men was over demonstrative, and neither was lacking in the ability for years and years of the hardest kind of work, but together they made an ideal team for taking up the invention of something that all the scientists of the world hitherto had failed to develop. Wilbur was called by those who knew him one of the most silent men that ever lived, as he never uttered a word unless he had something to say, and then he said it in the most direct and the briefest possible manner. He had an unlimited capacity for hard work, nerves of steel and the kind of daring that makes the aviator face death with pleasure every minute of the time he is in the air. No less daring is Orville, the younger of the two, who is a little bit more talkative and more full of enthusiasm than was Wilbur. He was the man the reporters always went to when they knew the elder brother would never say a word, and his geniality never failed them. He also is a true scientist and tireless in the work of developing the art of aviation. First, the brothers read all the learned and scientific books of Professor Langley, and Octave Chanute, the two first great American pioneers in aviation, and the reports of Lilienthal, Maxim, and the brilliant French scientists. They saw, as did Professor Langley, that it was out of the question to try to make a machine that would fly by moving its wings like a bird. Then they began with great kites, and next made gliders--that is, aeroplanes without engines--for the brothers knew that there was no use in trying to make a machine-driven, heavier-than-air flier before they had tested out practically all the theories of the earlier scientists.