Faraday to James Timmins Chance   23 April 1861

[Royal Institution embossed letterhead] | 23 April 1861

My dear Sir

I have had your letter¹ but I can say little to it. All my experience has been that when the oil is fairly burnt the light produced is in proportion to the quantity of oil but I have had only small experience with light house lamps[.] It is quite within the range of the possibility that the same quantity of oil may produce different quantities of light according as it is burnt[.]

If I understand rightly you consider that your lamp with excessive overflow gives more light for the same quantity of oil than the French or Scotch lamp do. That is a point to be established by experiment and comparison & is a very important point if established[.]

Ever My dear Sir | Yours Truly | M. Faraday

Jas Chance Esq | &c &c &c