Faraday to James Timmins Chance   30 November 1860

[Royal Institution embossed letterhead] | 30 Novr. 1860

My dear Sir

I arrived at home all well¹ and I hope you enjoyed your dinner[.]

I think I remember up the results pretty well.

As concerns the Manufacturer I do not see how he can adjust his panel without taking each rib separately; which I think is what you mean. As to the party examining; he is to have the right of examining each rib separately from foci given: & (I think) that we agreed that in respect of the dead level the focus for the chief band & upper ribs was to be 20mm (the chief band being the starting point) and for the lower ribs 11 up & 36 aside. Will not this be right for the Smalls? or shall 20 be made 21?

As the Smalls light is 125 feet above the water will there not be 12½ minutes of dip to the Sea horizon? and will not this require a lamp elevation for the refractors of about 3.3 millimeters?

Ever Truly Yours | M. Faraday

J.T. Chance Esq | &c &c &c