TALBOT6564

Oxford
Feb. 3^d 1852

Dear Sir

I have lately, from circumstances, had my attention recalled to the subject of your pamphlet ¹ on Foucault’s experiment. I believe when I wrote ² to you before on the subject I was inclined to differ from you as to the probable success of the experiment you propose. I was led to think that it would succeed from the analogy which subsisted between it and that described by M. Gargot[?]. I have however subsequently been convinced that those mathematicians are right who consider that there must have been some fallacy in that experiment – and in Consequence I now entirely agree with you that the experiment imagined of a bar freely suspended & balanced horizontally would not end in any apparent deviation due to the earth’s rotation.

This experiment seems to be the same in principle as that proposed by M. Baudrimont ³ (Comptes Rendus N^o 8. 1851) although this last is complicated by the influence of the torsion of the thread. It was objected to by some on that account – But there seems to me another reason applying to both. viz. that that [sic] the theory of Binet ⁴ & Foucault cannot be applicable to these cases inasmuch as that theory essentially involves the assumption that the body has an impressed motion given to it. it cannot therefore apply to a body at rest. If so I think your objection to the proposed experiment would not Constitute any ground for rejecting the theory of Foucault’s result.

Should you be giving any attention to the subject again I should feel obliged by hearing whether this view of the matter appears open to any objection & remain

Very sincerely yours
Baden Powell