Faraday to Second Earl Granville¹ and Robert Lowe²   Late July 1861³

To the President and Vice-President of the Committee of Council on Education.

My Lords,

A Commission of which I was a member was appointed in the Summer of 1859 to consider the lighting of Picture Galleries by gas, and the manner in which that object had been attained in the Sheepshanks’ Gallery at Kensington. The Commission made their Report in favour of that application on the 20th of July 1859⁴.

I have been desired to re-observe the Gallery with reference to the temperature communicated by the gas to the wood-work nearest to it. By the application of thermometers against the wood-work above and nearest to the gas-lights, it has been ascertained that at the present date the action of the heat after an hour’s continuance has been an elevation of temperature equal, occasionally, to 12° or 13°; i.e., the wood-work which before gas-lighting was at 71° became 84° in the course of an hour or so, and did not rise after any longer time. In the Sheepshanks’ Gallery the sky-light is double, and serves as the hot-air exit passage. The air in that passage being 75° before lighting became 91° an hour after and rose no higher. The part of the Gallery below the top of the Pictures was not raised in temperature more than two degrees by the lighting of the gas.

I have no change to make in any of the conclusions contained in the former Report; but on looking at the Sheepshanks’ Gallery at this time as an experimental attempt to light Pictures by gas, am still of opinion that the process there carried out fulfils the condition of effectually illuminating the Pictures and at the same time removing the products of combustion; but I desire to add the recommendation that the roofs of such Galleries be of Iron.

A Paper has also been submitted to me containing letters by Mr. Braidwood⁵ and Mr. Sydney Smirke⁶ of the 11th and 12th April 1861, regarding the application of gas to the lighting of the British Museum. It forms a Report to the Trustees⁷. The British Museum and the Kensington Galleries differ so much, that opinions proper to the one may have no application to the other. Many of the objections made by Mr. Braidwood in respect of the British Museum of which case alone he speaks are met by Mr. Smirke; as the removal of all mischievous vapours and the safe conduction and dispersion of heat; objects which can be attained, according to Mr. Smirke by sufficient contrivance and outlay. I should greatly hesitate to recommend gas-lighting in the British Museum against the opinion of the Architect who alone is aware of the construction of the building, and also of the dangers by fire which it may involve. Further, I am very strongly against the common practice of erecting a church or other building by one set of hands under one mind, and then giving it over to another authority and set, for the introduction of gas apparatus and pipes, or pipes of hot air or water (frequently at high temperatures and pressures) into parts and places where no intention respecting them had existed before; where no preparation had been made for them; and where the final arrangements must partake more of accident and risk than of premeditation and forethought.

I have the honour to be | My Lords, | Your Lordships most obedient servant, | (signed) M. Faraday.

Endorsed by Faraday: Lighting Gallery & Museum by Gas | 5.5 returned for report⁸