ROYAL OBSERVATORY
EDINBURGH
July 1 1863
Dear Sir,
I am very glad to hear of your having taken time yesterday by the fore-lock, for today Mr Banks reports the first Guajara as beginning to fail, & at the 100th impression, whereat he has accordingly stopped printing.
I have been to see the plate, & found the chief part of the mountain detail still very good; but there is an ominous bleaching of the foreground, and of the upper part of the high mountain peak. this latter instance is important, because it is precisely there that the dark tint is wanted to disprove the real existence of the apparent fine white blocks in the photograph.
Now failing at the 1st hundred is serious, when 500 are wanted, so I have proceeded in this way. 1st, I have told Mr Banks to prove the plate new plate as soon as you can let him have it, in the usual way, and then to square the picture and put in the lettering, making it quite ready for printing, but not printing until further orders.
2nd, I have been to see a Mr Thomas Dick in the old town, a poor, frail old body but an interesting sort of a genius of a man, who engraves, multiplies engraved plates by the electrotype, and sometimes coats them with steel by the same process. So as soon as the next Guajara plate has been proved, lettered, & prepared for printing, I propose to let Mr Dick try if he can put on so thin a coating of steel that Mr Banks shall not complain the engraving is filled up, while the surface shall be so improved in hardness as to bear 400 copies being pulled off without any sensible loss of quality below the first 100.
& I remain Dear Sir Yours very truly
C. Piazzi Smyth
H. Fox Talbot Esqre
[envelope, flap imprinted "Royal Observatory Edinburgh":]
H. Fox Talbot Esqr F.R.S.
Millburn Tower
Hermiston
near Edinburgh.