TALBOT4697

Lacock Abbey, Chippenham
12 Jan^ry 1843

Sir

M^r Watkins ¹ having mentioned to me that you were going to give a lecture on the 10^th Feb. at the R. Inst^{n 2} on Electromagnetic Machines, ³ I take the liberty of addressing a few lines to you on the subject.

I have recently had an engine constructed, which I believe to be more powerful in proportion to its size than any hitherto made, and I should be happy to lend it to you for the occasion, only that it is now undergoing alteration and I doubt whether it will be ready in time – A previous attempt I made was not successful owing to the proportions being not well adjusted: but the present, from a preliminary trial, has considerable power. It is made on the principle for which I took a patent ⁴ two years ago, and the description with figures will be found in the Repertory of patent Inventions. M^r Davidson ⁵ is exhibiting a small engine on the same principle at the Egyptian Hall, ⁶ it is employed to work a small saw – The principle of my Engine consists in this, that the armature lies quiescent on the magnet during nearly half the time – or in other words, that when it strikes the magnet, the rest of the mass in motion is disengaged from it. Wheatstone’s excentric [sic] Engine ⁷ is a joint invention of Professor W. and myself, if it were worth while we could point out the share which each of us had in it – Practically speaking I think my own arrangement most likely to produce a real working engine –

I am Sir Your obed^t Serv^t
H. Fox Talbot