The daily morning journal and courier., 1897-06-18

AAASAA' IAlllIS DOOA Oll SlOIlldCl uISSdStS mailed free.
 distance of over nine hundred feet from the point at which 1t rose. This, how ever, was by no means the length of it's flight. I estimated from the diameter of the curve described, from the num- Der of turns of the propellers as given by the automatic counter, after due all loWance for slip, and from other meas ures, that the actual length of flight on each occasion was slightly over three thousand feet. It is at least safe to say that each exceeded half an English mile.
 From the time and distance it will be noticed that the velocity was be- tween twenty and twenty-five miles an hour, in a course which was taking 1t constantly up hill. I may all that on previous occasion I have seen a far higher velocity attained by the same aerodrome when its course was hori- zontal"
 Later the aerodrome accomplished a flight of more than three-quarters of a mile in one and three-fourth minutes. The machine, of course, is built to car ry no weight other than it's own. Octave Chanute follows out a differ ent course of experimentation, which he tells of in his article, Recent Experi- ments in Gliding Flight" recounting a | course of trials made with various soar ing machines on the sand hills east of Chicago. Some of these contrivances had but two wings, some as many as twelve, and hundreds of soaring expe- ditions were made from the low hills across the sandy levels for distances varying from twenty-five to one hun dred and twenty-five yards. The only motive power was the wind against which the aeronaut sailed, suspended under and between his wings. Some | interesting facts regarding the little un- | derstood action of the wind were dis covered during these experiments. MT. | Chanute says, speaking of the advan- i tages of actual flight by the experi- menter:
 l Experiments with models are in structive, it is true, but they do not re- veal all the causes for the vicissitudes which occur in the wind. They do not explain why models seldom pursue ex- actly the same course, why they swerve to the right or left, why they oscillate or why they upset When man is rid | ing on a machine, however, and his | safety depends upon the observance of all the conditions, he keenly needs what is happening to him, and he gets entire ly new and more accurate conceptions of the character of the element which he is seeking to master.
 'The fact which most strongly i'm pressed itself upon us was the incon- stancy of the wind. It is necessarily changing in direction and in strength This fact is not new; it has been well shown experimentally by A. r. Zahm by Professor Langley, and probably by others; but its effect upon man-rid- den machine must be seen and felt tC realize that this is the great obstacle tc be overcome in composing artiflcia flight. It cannot be avoided, it cannot
 be temporized with, and it must bt
 coped with and conquered before we can hope to have a practical flying ma.
 chine.
 | "One remarkable feature of the wind
 however, struck us as hitherto un
 known, or at least unmentioned. Tht wind gusts seem to come in as rolling
 waves, rotating at higher speed thar the general forward movement. Tht buffetings which the apparatus received 1 from the wind while the operator wa! I endeavoring to steady it, preparator,
 to a flight, seemed to indicate that h, was struggling with a rotary billov
 which produced the fluctuations. It il i i+o nooiuoo ola that fhn Hnp ti0Y1! should be produced by revolving mo tion, striking the surfaces with veloci ties varying with the distance from thu
 center Of rotation, and producing al
 the pulsations which have been re
 vealed by the instrumental measure | ments.
 "Mr. Herring first called my attention to this feature of the wind, and I hay,
 ever since been wondering how l could
 for so many years. have been watching | smoke curling away from chimneys
 steam convolving from trains, or dus
 and leaves whirling in wind gusts | without realizing that the elastic tenui
 ty of air must perforce produce rotar!
 motions much more active than thos
 which occur in water.
 This observation, if confirmed b,
 further investigation, promises to giv
 us better understanding of the force
 to be mastered. There are indication
 that there is a certain synchronisn about these air waves, and that ar
 engagements can be devised not only t
 encounter them, but to avail of them il
 securing propulsion and automatic sta
 bility"
 Of the results in general MT. Chanut
 says:
 i've performed nothing like continu
 ous soaring with any of the machines