October 4th, 1880.
My Dear Sir,—I have given your 8-1/2 in. mirror one night’s trial, and it has greatly pleased me. Its resolution of the great cluster in Hercules was truly magnificent, and the clearness with which it brought out stars very difficult with 6-1/2 in. was highly gratifying. I hope to turn it to very good account.
Yours faithfully,
(Signed.)
Mr. G. Calver.
(Fig. 1.)
