Faraday to Jacob Herbert   22 September 1853

Royal Institution | 22 Septr. 1853

My dear Sir,

I have been in the country for some time & hence the delay in my reply to your letter of the 14th¹ instant in which you ask me for an opinion on the best form of belfry for a bell at the South Stack Lighthouse. This I find it difficult if not impossible to give you for I have had no experience nor any opportunity for observation in such matters up to this time. I do not know the particular locality now under consideration & have not visited any lighthouse or signal bell anywhere: nor have I yet had occasion to seek access to that experience which has been already obtained by others[.] I can therefore do little more than refer back to the vague generalities of my former letter (24 March 1853²)[.]

Still I venture to utter a surmise or two. I think it probable that the bell should be covered over, but I should not expect that a dome would be the best form but rather a flat surface and I think that the distance of this surface would be influential & perhaps importantly so. The surface under the bell probably ought to be regular - flat or perhaps even conical. If the sound has to do duty only for a part of the horizon as for instance 180˚ then probably a wall-back on the other or unimportant side might be very valuable, but I am really unwilling to offer further notions without communication with those who have had experience in these matters. In any site where a bell is to be placed I conclude that the form of the ground and also of the near buildings will have to be considered in reference to their acoustic influence³[.]

I am | My dear Sir | Your faithful Servant | M. Faraday

Jacob Herbert Esq | &c &c &c