Faraday to Peter Henry Berthon   12 August 1861

Royal Institution | 12 August 1861

Sir

I have just received the accompanying report from Mr. Chance¹. The alterations he has made in respect of foci &c are in full accordance with what I took the liberty to recommend to the Board and though I have not seen the lighthouse. I have the fullest confidence in their correctness. The change in height of the whole optical apparatus is (according to the description) a manifest improvement. I should certainly like a record of the foci, and the dip of the sea horizon to be permanently fixed on the apparatus as mentioned in my last to you²[.]

I have the honor to be | Sir | Your Very faithful Servant | M. Faraday

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