AERIAL NAVIGATION.

Globe, Volume XXIII, Issue 2413, 29 December 1881, Page 4

AERIAL NAVIGATION.

Mr !P. W. Brearey, a member of the Aeronautical Society, read on interesting paper in the Birkbeek Institution, Southampton Buildings, on aorial navigation, explaining with the aid of models, the principles upon which attempts had hitherto and should in the future be mado to efieot artificial flight. The conclusion at which tho Aeronautical Society had arrived was that, flight was merely a mechanical aotion capable 'it imitation, that it was unassisted by air colls or other contrivances for effecting levity, that tho_ balloon was incapable of being rendored useful toman as a means of locomotion except in the way of waftage, and that this mode of progression in relation to the earth was capable of being materially assisted by some method of raising or lowering the balloon at pleasure without loss of gas or ballast. After pointing out some of tha conditions uuder which a fish moved in the water and a bird in the air, he ■aid he was quite prepared for the discovery of some peouliar condition attachinz to the agitation of this thin medium of which we had no conception. The tenants of the air, great as was the variety in their size and form, resembled one another in possessing three important capacities, the association and proper adjustment of which constituted tho property and power of flight—viz., weight, surface, and force. The weight of a body was due to the aotion of gravity, and the problem was how so to retard or regulate tho action of gravity as to cause its influanoe to be infinitesimally distributed. Having explained what he wished to show by projecting iome peouliarly-folded pieces of paper across tho theatre, be then let fall from a .height a bat-shaped model, whioh soon, taking a onrve, shot out in a nearly horizontal direction for a time. Had force, the tnird great principle of flight, been employed, it would have neutralised the action of gravity so long as it oontinued, and the flights of the models would have been prolonged. In endeavoring to estimate the proportion of plane surface to weight, so that the ono might carry the other by the application of impulsive force, we were not without sigriifioant data. Bo varied were the forms of flight and so widely different the conditions—in some cases a heavy weight being supported by Bmall planes or wings and in others little weights by extensive surfaces — that if evor the subjeot should be mastered, flight would probably be effected in more ways than one. Great woight and small surface, as the observations of M. de Jjuoy showed, mußt be aooompanied by great velocity, as in the flight of the common sparrow, while with small weight and great surfaoe, as in the butterfly tribe, a reduced velooity only was requisite. IF, therefore, man could construct the teoessary surface of strength sufficient to insure safety, he oould certainly add, by the aid of en»ine-power, sufficient Telocity to obtain support upon the atmosphere. Showing this by the flight of models with wing surfaces of different forms, whioh were propelled by the torsiin of andiarubber bands, he then gave an account of experiments whioh had been made within the last thirty years. It was to be regretted that many were working in secret, and thus the oanses of failuro were not generally known. Ono reason for this seoreoy was the fear of ridicule ; another the state of the patent laws. He had himself turned his attention to the paraohute, because it was known that a surface of thirty square yards would bring a man safely to ground, and his efforts had been directed to providing a means of propulsion. He was not without hope, especially since he had held a oonvorsation with Dr. Siemens at York, that in eleotrioity wonld bo found the means of supplying a foroe which would make it possible to transport a weight of say, 3001 bin the air.—" Times,"