23 Red Lion Street Whitechapel <1>
27th Oct 1842
Respected Sir,
In answer to yours of yesterday, allow me to say that the Machine is so far useful, as fits it to be placed in a Scientific Institution, which, I presumed it should be, shewing that another step had been attained in the Science by the production of a Machine more powerful than any hitherto made, of any size. I beg to call your attention to the fact; that with one or two exceptions, all Electro-Magnetic Engines, yet made, have been mere Toys, with just sufficient power to move themselves while this works with a weak Battery, and, with a strong one possesses considerable power and, I flatter myself wherever it may be placed, will reflect no discredit on either the Inventor or Manufacturer I speak thus not only from my own judgement but from that of several Scientific Gentlemen who have witenssed its performances who all expressed an opinion that if it were publickly exhibitied you would be considered the first Electro-Magnetician in the Country as you had made the greatest advances towards its being of practical utility
I have no doubt that in the construction of another Engine several improvements might be introduced altho I am confident that a fac simile of this on a larger scale, would propel a Boat on a river, or Carriage on a railway Respecting the diminution of the throws, I will with pleasure make any alteration you may think proper, but, permit me to suggest the idea of One Magnet fixed on a piece of wood, with an Armature and connecting Rod, and an excentric pin miving in a groove that you might fix in any position you thought proper, in this case you could not fail to discover the most proper length of throw and distance of the Armature from the Magnet. you would also have the Iron Boxes fitted on the Poles this, furnished with a wheel, would form a little Machine, that with a Smees Battery,<2> you might perform a great many experiments
On looking over my Accounts I find I cannot charge less than Fifty six Pounds for the Engine and that barely pays for the Materials, labour, loss of time attending the various alterations and experiments, that it has had or Cost of Acid, Carriage Attendum &c this may appear a high price but I pledge myself it cannot be matched for the money by any other person in the Trade
The Cost of a Smees Battery of 12 Plates of 7 inches would be ten Pounds as the following scale will show
Platenized Silver for each Pair
Zinc and Amalgamation
Binding Screws labour &c
Cost of one
Trough & Cement
I have the honor to be Respected Sir your obedient Servt
W.T. Henley
Notes:
1. London
2. Alfred Smee (1818 1877) modified the copper-zinc cell in 1839, substituting platinum for the copper.