James Timmins Chance to Faraday   13 December 1862

Handsworth, Birmingham | 13 Dec. 1862

My dear Sir,

Nothing has, I believe, been done with the metallic reflectors of the South Whitby Light.

I have been considering matters of this kind of late; and I think that the center of the Mirror must have been placed too low in the flame, so that the inverted image fell partly on the burner, thereby causing loss of reflected light and injurious heat on the burner - thus:- the red lines are intended to indicate the inverted image: C is the supposed center of the reflector - say, in the focal plane of the lenses.

Now this defect is easily remedied by placing the center of the reflectors about the middle of the flame: thus: so that the inverted image will about overlap the original flame.

C center of reflection.

But, further, if it be desired to increase the vertical divergence of the flame, by raising its height, the center of the mirror may be placed above the middle of the flame. For Example, if the center of the reflectors be placed at the top of the effective flame, the angle of vertical divergence will be doubled, & very economically:- thus:- Indeed, where reflectors are admissible, this is a very simple way of heightening the flame, without any extra consumption of oil[.]

I have thought it better to make these suggestions, for your consideration;- especially as they concern the reflectors of the Whitby Light which were suspended for future determination[.]

Believe me, | Yours very truly, | James T: Chance

Professor Faraday | &c &c | Royal Institution