Dear Sir

My Mother has forwarded your letter^<1> to me but I have not the means of obtaining a sight of Cecils^<2> Invention of a Gas Engine – Adore’s Patent^<3> was confined to the modification which was peculiar in asmuch [sic] as the means of [illegible deletion] igniting the Gas – the whole is very crude & I believe was never tried The Patent for Browns^<4> Gas Engine has expired he made several Engines and some of large dimensions but it is generally understood that the cost of obtaining the Gas rendered them much too expensive in use they worked very well – they are all out of use.

From my knowledge of the various propositions for making Engines to be worked by Gas I am of opinion that any practical mode of constructing an Engine which would work advantageously must contain material novelty which might become the subject of a Patent At the same time I have but little hope that Gas as a means of producing a vacuum with a view to obtain power does not will with our present knowledge of be found beneficial – In any case the practical difficulties were generally considered to have been overcome and the last of his Engines were very simple in construction equally so with the Steam Engine and for several years Brown turned his attention to means of working gas with a view to reduce its cost and he made it from water & from peat but as far as I am informed the cost and trouble of obtaining the Gas was too much for him – With respect to the Invention of Mr Ador it appeared to me that the cost of obtaining the Gas will be much too Cost great even supposing the practical arrangement of the Engine were more complete –

Your obd^t Serv^t
William Carpmael

5 Albion place
Ramsgate
Augt 24^th 40

H. F. Talbot Esq

P.S. We cannot at present inform you when your opposition to M^r Stirling^<5> will be heard the [illegible deletion] neither the Sol^r or Atty. Genl. being in Town –

Y^r Ob^t
Poole & Carpmael

H. F. Talbot Esq
Lacock Abbey
Chippenham

p.p.

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Notes:

1. Letter not located.

2. Rev William Cecil (1792–1882), a fellow of Magdalen College, Cambridge, demonstrated a working model gas engine in 1820. His 27 November 1820 paper was "On the Application of Hydrogen Gas to Produce a Moving Power in Machinery; with a description of an Engine which is moved by the Pressure of the Atmosphere upon a Vacuum caused by Explosions of Hydrogen Gas and Atmospheric Air", published in the Transactions of the Philosophical Society of Cambridge v. 1, 1820, pp. 217-239.

3. A misspelling of Ambroise Ador, a London chemist who in 1838 was granted patent No. 7547 for improvements in motive power using a hydrogen engine.

4. Samuel Brown, a London engineer, patented his first engine in 1823, and an 1826 improvement powered a vehicle up Shooters Hill. Although inefficient, it found some uses in nautical applications.

5. Rev Dr Robert Stirling (1790-1878) of Galston, Ayrshire, designed an engine that recycled waste heat. His second patent, in 1840, was taken out jointly with his brother, James Stirling, a Dundee Engineer who employed a working engine in his factory. [See also Doc. No: 04124 and Doc. No: 04132].