Joseph John William Watson to Faraday   17 July 1854

Electric Power Light and Colour Company’s | Works, | Frogmore Lane | Wandsworth | July 17 1854

Sir,

In answer to your enquiries of Mr Tyndale¹, the secretary to the Company, relatin[g] to the forthcoming trials of my invention at the Trinity House I wish to inform you that all apparatus, materials &c will be delivered at Tower Hill during this week and that everything will be in readiness for experiment by Saturday next (22nd) or Monday morning 9 oC.

In regard to the height of the lamp from the ground that will depend entirely on the position in which you intend to place it - the elevation of the lamp itself when arranged for burning is 4ft. 6in. but this is not ‘en masse’ as I measure from the base of the lamp to the top of the rod carrying the upper-electrode: this rod of course could project through a very small apperture in any illuminating apparatus. As, however, there may probably be some questions you would like to ask me before making your photometric arrangements I will do myself the pleasure of waiting on you at 10 1/2 oC: on Saturday morning at the Institution when the plans for Monday can be decided on²[.]

I am | Sir | Yours very faithfully &c obediently | Joseph J. W. Watson

M. Faraday Esq D.C.L | &c &c