Until the summer of 1911, the longest model aeroplane flights officially recorded in America remained under 300 feet. From England meanwhile came disquieting reports of 1,000 foot flights and better, made by a number of aeroplanes. A comparison of the best American and English models showed that, both as regards form and workmanship, American boys were holding their own against their English cousins, and utterly failed to account for the much greater distance qualities of the foreign models. In July, 1911, the American distance record was suddenly jumped to 1,691 feet, 6 inches, by Cecil Peoli of New York. The model used had been flown in the regular indoor meets for very much shorter distances. This sensational advance in the distance record was made at an outdoor tournament at Van Courtland Park, New York City. Of the thirty-four models entered for the contest, including the familiar models built by Percy Pierce, H. Watkins and others, several showed a similar increase in distance qualities. The model aeroplanes were the same as had flown but 200 feet indoors, their rubber motors exerted no more power than before, the pitch of the propellers remained unchanged. What then is the secret of the suddenly acquired distance qualities? Evidently the difference lies in the quality of the air the little ships navigate. It is commonly said that the air indoors is dead as contrasted to the live air found out-of-doors. The variation in the quality and movement of the air forms a very interesting study which no aviator can afford to neglect. To the actual navigator of the air this study is just as important as life and death, while to the designer even of model aeroplanes it is of course of vital importance. Although the composition of the air and its behavior under various conditions has been the subject of scientific examination for centuries, "it is only within the past few years that it has been studied with the idea of bringing it under control. The long painstaking experiments of Langeley and Lilienthal, referred to in the previous volume, for determining the resistance of the air and its effect on the surface of the aeroplane, opened a new field of scientific research. Within the past few years, even months, the advancement in our knowledge of the air has been greater, it is safe to say, than in the previous century.