James Timmins Chance to Faraday   17 November 1860

Hamstead | Birmingham | 17 Nov. 1860

My dear Sir,

I enclose a memm of what has been done at Whitby¹. If anything in it appears to you to require alteration, be kind enough to return it, & I will make any change wh: you may wish.

To whom shall I send the bill of the expense of the alterations?

I am working at the preparations required for you to determine the lens question. I find that 28mm sends the brightest light of the middle belt much above the horizontal line:- and yet, as Captn. Ryder says, Mr Stevenson has arrived at results so different that he considers it unwise to allow for such a Sea-horizon dip such as at Whitby, on the ground that the highest light through the lens goes from a part of the flame above the 28mm

This question, then, becomes a very important one. I hope on Monday² to let you know something definite concerning the time when I shall be ready for you.

Even now, however, whenever you like, I can shew you the comparative effect of different heights of focus for each lenticular band by itself: and for my own part, I much prefer this analytical way of investigating the subject rather than examining the total effect, unless we could do this at a very great distance, and then it is about impossible to form an accurate judgement as to comparative intensities. But if each lenticular band by itself is made to send the brightest light in a given direction the sum total will of course be the best possible arrangement.

Now be kind enough to say whether you would be content to arrive at the result in this manner, without having two complete panels:- or would you prefer waiting somewhat longer, in order to have the compound effect shewn, as well as the effect of each individual band?

Yours very truly | J.T. Chance.