Mr. Thomas Moy remarked that the popular mind was peculiarly obtuse to simple facts which should be easily grasped, and that even scientific men failed to appreciate the importance of the demonstrations whiqh had been worked out by that Society. The amount of success with models, he contended, were so palpable, that men of capital did not exhibit much wisdom in their non-encouragement of efforts on a larger scale. If a tin box of one cubic foot capacity, as shown in diagram No. 1, were filled with gas capable of raising one ounce to the cubic foot, and if the tin of which it was made weighed one ounce per square foot, then it would weigh six ounces if filled with air, and only five ounces if filled with gas.

“Drawing an inference from the extent to which the study of birds has been directed with the view of accounting for their manner of flight, we might have been designated an Ornithological Society, except for the fact that we only study the bird as a means to an end. That end being flight, and the examples in nature being varied, we can come to one sure conclusion: that the very thin element which surrounds our globe is capable of being made a high road for the passage of heavy bodies by a mechanical and continuous attack upon the medium, based upon a knowledge, in great part yet to be attained, of its action and reaction when somechanically manipulated.

Mr. Cradock prefaced his written observations by stating that the paper had been written a long time, and he had come to the conclusion that there was more evidence of the probable success of aëronautics than of many other successful things which had come before the public.

“When man’s weight and muscular power is properly applied to raise him it is clear he has the power. As by the use of three or four revolving stair steps which give motion to a pinion that gears into a vertical rack. On this revolving stair being set in motion by the man placing his weight upon the successive steps the pinion will elevate the man to as great an extent as if he employed the same labour in walking up an ordinary stairs. The question is not one of power, but of suitable means to utilise man's power.

“The principle by which birds overcome the action of gravity is commonly assumed by investigators to be the superiority of the resistance of the down stroke of the wingto that of the up. They assume that birds fly by thedifference of the resistances.

“I have already shown in a former Paper how flighttakes place by the proper resolution of the two resistances. I will now demonstrate the utter absurdity of the difference of resistance theories.

“We will observe the action of a bird just on the point of leaving the ground—and in the study of flight, this, with the period of a lighting, is the most important for observation, as it is during these two periods that the bird exercises most the principles by which it overcomes gravity.

Since the days of Bishop Wilkins the scheme of flying by artificial wings has been much ridiculed, and indeed the idea of attaching wings to the arms of a man is ridiculous enough, as the pectoral muscles of a bird occupy more than two-thirds of its whole muscular strength, whereas in man the muscles that could operate upon the. wings thus attached would probably not exceed one-tenth of the whole mass. There is no proof that, weight for weight, a man is comparatively weaker than a bird; it is therefore probable, if he can be made to exert his whole strength advantageously upon a light surface similarly proportioned to his weight, as that of the wing to the bird, that he would fly like a bird. The flight of a strong man by great muscular exertion, though a curious and interesting circumstance, inasmuch as it will probably be the first means of ascertaining this power and supplying the basis whereon to improve, it would be of little use.