A GREAT and widespread interest has been aroused by the experiments now being conducted by Orville Wright at the scene of the first great flights by man, Kitty Hawk, N. C. Many reports have been circulated with regard to the real purpose of these experiments, some of them no doubt exaggerated and perhaps amusing to the taciturn Dayton inventors. Orville Wright's “vacation” is nevertheless an occasion upon which the eyes of the aviation world have good cause to look sharply. Other than to teach Ogilvie how to glide, and to test a “tail” glider, Orville Wright is evidently bent upon continuing in a logical manner the exhaustive experiments in free flight conducted over so many years by his brother and himself. The most startling achievements that have resulted from this latest series of tests are briefly as follows: In a biplane glider similar in many respects to the model B Wright machine frame, but differing in the smaller size of the planes and the use of a larger rudder, and slt- ting upright with the usual control mechanism in his hands, the aviator has succeeded in making glides that far exceed anything done in this line before. He has attained greater heights, greater distances, and stayed aloft a longer time. The general character of the glides, however, bears much resemblance to the 1903 experiments. On Monday, October 23rd, a curious accident took pla c e. R i s in g some twenty feet from the side of the hill, the heavy rear rudder appeared to become uncontrollable and to make the glider so “tail heavy” that it began to t urn ov e r and s tart backward, whereupon M r . Wright climbed to an upright position of safety on the overturning mac h i n e with such excelle n t j u d g ment that when the apparatus struck the ground and sm a shed Mr . Wright emerged unhurt. This experience suggests that many of the fatal accidents in a v i a t i o n were avoidable by the same sang froid. Of course the lighter loading would make the time of fall in such an emergency, longer as well as render the shock lighter. On the next day, October 24th, a feat that has long been predicted and looked forward to was ac- complished. With consummate skill Orville Wright soared aloft into the teeth of a supposedly fifty-mile gale, and succeeded in not only soaring for a period of almost ten minutes but in actually advancing into the wind. This great flight was made over the side of the hill facing the wind so that the air currents must have had a decidedly upward trend. The distance covered by the flight was a quarter of a mile and the height attained estimated at 200 feet above the surface. Though the results are astonishing to many, those familiar with the nature of air currents expect even more startling performances at an altitude three or four times as great. It is hardly possible as reported that the object of these tests was to try out a device for automatic stability. There is not yet enough known of wind cur- November 4, 1911 SCIENTIFIC AMERICAN 405 rents and their motions to enable a thoroughly successful device £If the sort to be even conceived. It may be definitely assumed that the purpose of Orville Wright's experiments are primarily to learn more of wind conditions. Many problems such as the avoiding of “sideslipping” still remain to be solved. Not until every possible vagary of the air currents becomes known, can a device for automatic stability be designed and be successful. It is due partly to the peculiar phenomenon often called “Lilienthal's Tangential,” that a glider with cambered planes can not only remain stationary but in a wind of great enough upward trend can be made to actually advance without the exertion of any motive power whatsoever. This would appear offhand like perpetual motion, but it must be borne in mind that the huge energy of the rising current itself is the source of power. The phenomenon referred to is merely, that at certain angles, the total air pressure acting on a plane ceases to act in a line normal to the plane or its chord, and instead the line of action of this force takes a position well in front of the normal, the pressure thus materially acting in the dual role of a supporting and propelling force. Octave Chanute, early in 1909, pointed out in a masterly way the manner in which this problem of soaring could be solved and many experts since then who have investigated the problem are convinced that it is a feasible one, even though it appears to defy physics. These experiments of the Wrights are therefore likely to bear fruitful results—results that may eventually become of the utmost importance. It will be interesting to note what changes in their standard design the Wrights will make as a result of these tests.