WCP2127

[1]

SELBORNE,

47 CARTLAND ROAD,

HAZELWELL.

Jan. 5th 1912

Dr A. R. Wallace.

Dear Sir

I am very much obliged to you for your kindness in giving me the information I asked.

Prof. Benzley¹ of our University is an old friend of mine and I have no doubt that through him I shall be able to see the book.

[2]

The actual mechanics of the flight of the diptera, as regards the movement and adjustment of the whole wing is, I believe within the reach of invention and the petrol engine, but the structure of the wing, so that it yields to air pressure in the correct form to give the maximum efficiency of propulsion and the minimum dead resistance is a complicated matter of which [3] I hope to learn something, as I have done in mechanics, from nature.

Again thanking you, | I remain | yours faithfully | F. L. Ball [signature]