20 Conduit St <1>
March 1st 1841.
My dear Sir
I duly received your cheque for ten pounds.
I had foreseen the liability to explosion from the cause you mention and had requested the workman to furnish the model with a safety valve, but as I found the expence would be thereby augmented I resolved for the present to do without it. I intend to keep at a respectful distance during the experiment and to use one of my telegraphic connectors <2> so that I may break the circuit from a distance before I have occasion to approach the instrument. It may however be as well to take the additional precaution you suggest. I have devised an extremely simply safety valve for the engine <3> itself, but I do not think it can be added to the present model.
Your new photograph <4> excited great much interest at the Marquis’ <5> on Saturday. The artists generally greatly prefered [sic] it to the more elaborately finished Daguerotype [sic] portraits which were also exhibited there. One academician said it was equal in effect to any thing of Sir Joshua’s. <6>
Yours very truly
C. Wheatstone.
Notes:
1. London.
2. In 1837 Wheatstone and William Cooke had patented a needle telegraph, called ‘The Cooke and Wheatstone Telegraph’.
3. On 7 July 1841, Charles Wheatstone was granted a patent for the regulation and application of electric currents, primarily for an magneto-electric machine, or an electromagnetic engine as it was called.
4. Wheatstone helped WHFT promoting the calotype process on more than one occasion. [See Doc. No: 04279].
5. Henry Petty Fitzmaurice, 3rd Marquess of Lansdowne (1780–1863), MP, WHFT’s uncle.
6. Sir Joshua Reynolds (1723–1792).