Jacob Herbert to Faraday   1 September 1852

Trinity House | 1, Sept: 52

My dear Sir,

I thank you for your note of yesterday¹ - and now send you an extract from the French official publication of Light Houses in France², which as it describes the practical Operation of a dioptric Light of the Second Order revolving, may be of some use in your Consideration of the subject of the Caskets.

Upon the whole perhaps it may be better that you should make the proposed enquiry of the Construction of the dioptric Lights in Paris, - and, if you see no objection, perhaps you will do so.

The Deputy Master³, is disposed to think that, if there be any doubt of preserving the present appearance of the Lights, by substituting a dioptric arrangement instead of the present circle of reflectors, - that it may be as well to consider whether it would be advisable to encrease the power of the Light, by having two circles of reflectors in each Lantern, - they being placed vertical, so that the axis of two shall be precisely on the same Line.

I remain, | My dear Sir, | Very faithfully yours | J. Herbert

M: Faraday Esq