_From_ THE REV. CONYBEARE W. BRUCE, M.A., F.R.A.S.
ST. NICHOLAS’ RECTORY, CARDIFF, _July 17th, 1880_.
MY DEAR Mr. CALVER,—You will have been looking for some news of me and the 12″. I have purposely delayed writing until I was _really_ in a position to say something definite, and you had already heard my high opinion of the mirror. Let me at once say that that opinion has been _more_ than justified. The mirror is a _beauty_. Canon Beechey and I got Jupiter and Saturn at 2.30 a.m. yesterday morning—and they were _superb_. The Canon declared enthusiastically, that he “had _never_ seen Saturn anything like that,” and the last thing he said to me on the subject as I parted with him to-day was, “You have got a very fine instrument indeed.”
If I _could_ add anything more in its praise it would be this, that I am really going to build a _new observatory_ for it—my present one is too small and cramped.
Sincerely yours, (_Signed_.) Mr. G. CALVER.
(_Another Letter from the same Gentleman._)
ST. NICHOLAS’ RECTORY, NEAR CARDIFF, _August 28th, 1880_.
DEAR Mr. CALVER,—The 12 inch surpasses all my expectations. It has the perfection in figure of the incomparable 10 inch of yours, which was its immediate predecessor, and, in grasp of light, the difference in favour of the 12 inch over the 10 inch, a most brilliant mirror, is simply astounding.
You may equal the 12 inch—I am sure you will, whenever you make one—but you will not easily beat it. Mr. SADLER, the well-known and most accurate observer, has himself worked with it, and writes of it to me as follows:—“The 12 in. is considerably superior in light grasping power to H2’s 20 ft. reflector, and the figure is a much finer one.”
Your skill and kindness has placed me in the front rank among amateur observers, as far as the possession of optical means is concerned.
I was afraid that the German Stand would not prove so convenient as the “Berthon Equestrian Stand,” but I find it is and far more so. The German Stand is, for anything above 6 in., decidedly more solid and dependable, and far simpler in any case. The merit of the “Berthon Equestrian” form is that it requires a smaller observatory.
MY DEAR SIR,—As the 11-1/4 in. speculum has now been in constant use for two years, I may be allowed to express my opinion, with all due deliberation, as to its performance. It has been tried upon almost every conceivable object during that period with uniformly good results. Having also a 5 in. achromatic of the finest quality, I have been enabled to make a great number of comparisons between the two instruments, mounted side by side: and for fine definition, smallness of star discs, and freedom from chromatism, the reflector always came out victorious. Upon first mag. stars, nothing could surpass the purity of the image in the reflector; but on immediately turning to the achromatic, the outstanding violet rays were painfully obtrusive. For red stars, which are generally small, the reflector seems especially adapted. I used to be rather sceptical about the tints of red stars, but must confess, after seeing the magnificent tints of scarlet and crimson which are shown by a large aperture, that my doubts have vanished. Definition upon the planets, in good air, is simply perfect. The detail on Jupiter and Saturn reminds one of an exquisite engraving. The far distant Neptune is perfectly defined as a tiny disc, and his moon steadily visible with the 11-1/4 in. The faculæ and other Solar detail are brought out with wonderful distinctness. As for the Moon, the crispness of definition, absence of colour, and immense number of minute objects shown by the reflector, leave nothing to be desired. The gorgeous views of clusters and nebulæ: the brilliantly crowded fields in the galaxy: and the endless variety of star colours and groups are almost beyond description, and must be seen to be appreciated. I could fill pages about objects seen with the 11-1/4 in. mirror, but will not occupy more space, save to thank you for having placed such perfect instruments within the reach of amateurs.