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.

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.

“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.

“The subject of flight is one which ought to be approached in the most unprejudiced manner, and so great and many are the advantages and benefits that would accrue to the human economy by its realization, that it at once places itself as the highest and noblest aim for the inventive mind.

“That aërial navigation is possible there can be not the slightest doubt, we have so many and so varied illustrations in nature; it may probably be on account of having such a variety of natural models continually before us, that the one true principle which governs them all is hidden amidst a complexity of means. There are birds, insects, and animals, capable of controlling and making subservient to their will the most unruly of the elements; is it too much therefore to expect that man, created lord of all, who has outrivalled by his in genuity and skill the power and speed of the strongest and swiftest of the animal creation,—is it too much to hope tha the shall by application unravel the mystery of aërial flight ?

“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.