London, N.,
September 6th, 1880.
My Dear Sir,—The 8-1/2 in. mirror which you supplied me with during the early part of the year, I have recently mounted as a simple equatorial. And although I have had but few opportunities at present of using the same, they have been sufficiently numerous to prove, beyond doubt, the great excellence of the mirror.
On the evening of the 3rd September, I had some beautiful views of Jupiter and Saturn. In the former the deep coppery hue of the equatorial belts, and of the large spot, at present visible on his southern hemisphere, were strikingly conspicuous, as were many minute details of his surface. In the case of Saturn, the gradations of light on the rings, and the delicately tinted belts on the planet itself, also the sharply defined shadow of the planet on the rings were easily seen.
Its definition of the most minute portions of the moon’s surface, leaves nothing to be desired, whilst its performance on double stars is equally satisfactory.
Yours faithfully,
(Signed.)
Mr. G. Calver.