Faraday to Jacob Herbert   18 January 1854

Royal Institution | 18th Jany 1854

My dear Sir

I have a letter from you of the date of 6th Octr 1853¹, yet to answer: I have not forgotten nor neglected it. I have had the opportunity of conversation with Mr Walker several times. I have also written to Cromer lighthouse to enquire what the effect of the changes lately made there according to my instructions had been during the recent very severe winter weather; when strong wind & cold had to be encountered and regulated:- The answer² is as follows & most satisfactory. “Sir - In answer to yours I send you the best information I can. The stove answers well with all winds by attending to the ventilation below: the lower lamps burn as well as the upper. We are all quite well. Yours &c Ellis N. Field³. Dec. 28, 1853”.

The result of this & other experience & a consideration of the principles concerned induce me to submit to the Trinity Board the following system for adoption in a lighthouse in the next possible case: I strongly anticipate such good results as may justify the recommendation of the plan (with more or less modification according to peculiar localities or circumstances) as a pattern in future cases. The watch chamber to be dry. The lanthorn & watch chamber to be cut off from the tower by a door as usual; and those for warming & ventilation to be considered virtually as one chamber. The ventilation as to entering air to be effected by the use of four windows in the watch chamber like those I have described in the Cromer report (29 Aug 1853)⁴ any one of which (according to the wind) will when open an inch or two be sufficient for the purpose. This air to be heated by a stove standing (unless there be special reasons) in the middle of the watch room. The stove not to be jacketted or double; or, if it be, both the top & bottom part to be removed:- The cross braces on which the lamp &c stands, support the ceiling of the guard room & the floor of the lanthorn about 6 inches apart; the space thus opened to be made hot air passage; by opening the centre of the ceiling of the Guard room for a diameter of 5 feet covering the space with a light grate or a screen of trellis wire work, and opening also the floor of the lanthorn all round for a distance of two feet or perhaps 18 inches from the wall. The guard room & the lanthorn to be separated by a door on the stairs for the sake of pure caution which may however not be finally needed. I expect that the air entering by the window open to windward in the guard room will be effectually warmed by the stove, will freely pass upward, & entering the aperture above will be diffused all round the lanthorn under the platform & glass - and do its proper work perfectly. I expect that a minimum quantity of coals & of air will be required to produce the desired state;- that the warm air will ascend freely & generally into the lanthorn;- that none but warm air will ascend;- that the air will be in a minimum degree of dampness in respect of that taken from the tower or other parts;- and that all the heat generated by the stove will be conveyed into the lanthorn. The chimney of the stove should be of copper as usual; should pass through the ceiling & floor to any convenient side of the lanthorn according to the nature & position of the latter; but should be within the lanthorn in its ascent, and if manageable on the coldest side. I do not expect that the usual ventilators in the sides of the lanthorn will be required; but I think they ought not to be dismissed in the first instance - or until the efficacy & sufficiency of the proposed plan has been fully proved.

Mr Walker does not see any difficulty in the construction; he now has the proposition before him for consideration and with a view to the preparation of drawings⁵[.]

I am | My dear Sir | Ever Truly Yours | M. Faraday

Jacob Herbert Esq | &c &c.