From Frank C. Dennett, Esq.
10, Terminus Terrace, Southampton,
December 10th, 1878.
Dear Sir,—The 5-1/4 in. is beautiful. Last night there was a slight frosty fog, and the air was very very steady, in fact I only remember about one such night since November, 1875. Saturn was sharp and hard, and the shadow of the ring intensely black, with all powers from 168 to 372, and even with 550, obtained by removing the field lens of 372. The very broad polar caps presented a bluish grey, rendered more visible by contrast with a fine penumbral line of a very slightly brownish grey close to the south border of the ring, and which seemed to be diffused on the south border (i.e., the line was diffused). I should fancy the line here referred to was less than 1″ of arc broad; considerably less!
Turning from Saturn, I looked at ε Arietis, the present distance of which is only 1″·17; with all powers, from 213 upwards, the components were visible as two tiny points of light thoroughly divorced, and with 288 power, reminding one of ε2 Lyræ, as seen with 120 on a 2-3/4 in. achr., only the discs seemed freer from rings.
Later in the evening, when the definition was more fluttery, η Orionis shared the same fate as ε Arietis, being well separated with the same powers. The present distance of this star is only 1″·12. Recently I divided this star with a 4-1/2 in. stop on the mirror, power 288. I have seen ε Arietis well with the same stop too. I think I have told you before that the 5-1/4 in., with 372 power, was successful in dividing ε Equulei, whose distance is only 0″·97. This is the closest star I have yet divided.
The Moon is fine too! Last night I caught a large ring close to the terminator, near the south pole (for the Moon was only about 2-1/2 hours past full), which was looked at over the northern wall; the view was beautiful, such gradations of light and shade, interspersed with greys of different hues, which render the object scarcely describable. The finest clefts and tiniest craterlets are rendered visible. It is a puzzle to me how anyone in the possession of £16 or £17 can go buying a refractor of from 2-1/2 to 3-1/4 in. aperture in preference to a silvered mirror. It must be from sheer ignorance of the beautiful views given by the latter, which is superior in every way.
I do not think there is any other point on which I need touch now, so I must beg to remain,