Faraday to Peter Henry Berthon   21 November 1859

Royal Institution | 21. November 1859.

Sir

In reply to your letter of the 17th instant¹ respecting the proposed fog bell for the Start Point and the four questions to which you desire answers, I reply, to the first, that in my opinion such sounding boards above & behind the bell would prove of much use: To the second that I think either wood or iron would be efficient; - and to the third that I should incline to plain iron in the doubt that corrugated iron might interfere with the numerous vibrations; - To the fourth,- I think the sloping of the platform would be useful but I am not prepared to say whether the covering of the slope with metal plates would be advantageous or necessary[.] I am not aware of the extent of slope surface.

In March & September of 1853, I had occasion to write to the Trinity House in respect of Fog bells &c² as far as I was able to form a judgement. These papers express my present opinions & I would beg to refer you to them, especially in reference to the uncertainty of the data concerning the application of Fog signals³[.]

I have the honour to be | Sir | Your Very Obedient Servant | M. Faraday

P.H. Berthon Esqr | &c &c &c