Page:Aerial Flight - Volume 1 - Aerodynamics - Frederick Lanchester - 1906.djvu/436

App. II. D. Society some time so as to let those interested have their choice.”

Neither paper materialised. Lord Kayleigh shortly afterwards published his article (loc. cit. ante) in the ''Phil. Magazine, somewhat modifying his earlier conclusions and anticipating publication by the author in respect of two of the results now stated, i.e.'', (1) the absence of momentum in or pressure due to a wave train under the conditions of Boyle's law; (2) the pressure of sound waves in a real gas as due to energy entering the thermodynamic system.

Before going to press the author submitted the above addendum to Prof. Poynting, and received the following reply, October 7th, 1907:—

“I stick to the postcard and have no objection to its publication.”

“My proof of pressure was practically identical with Rayleigh's and gave the result (1), and therefore I suppose (2). That is why the paper did not materialise.”

This is a truly astonishing statement in view of certain correspondence and MSS. in the author's possession. The following quotations are given as throwing some light on Prof. Poynting's actual position at the time in question.

In a letter dated June 7th, 1905, referring to a draft MS. submitted by the author, Poynting says:—

“On p. 3 the paragraph marked wants, I think, a few words inserting to make it clear.”