Notices of some parts of the surface of the Moon, illustrated by drawings

My first serious attempts to portray the aspect of the moon were made with the noblest instrument of modern times, the great telescope of Lord Rosse, in 1852. The mirror was not in adjustment, so that the axes of the incident and reflected pencils of light were inclined at a very sensible angle. This being met by a large reduction of the working area of the mirror, the performance was found to be excellent. I have never seen some parts of the moon so well as on that occasion. But when I came to represent what was seen, the difficulty of transferring from the blaze of the picture to the dimly lighted paper, on a high exposed station, with little power of arranging the drawing-apparatus, was found to be insuperable, and the effect was altogether disheartening. It was like setting down things ex memoriâ, to give the rude general meaning, not like an accurate and critical copy. I present as a specimen of this memorial a sketch of the great crater of Gassendi (No. 1). I next mounted, in my garden at York, a small but fine telescope of Cooke only 2·4 inches in the aperture; and, aware of the nature of the difficulty which beset me at Birr Castle, I gave it an equatorial mounting, without, however, a clock movement. The whole was adapted to a large solid stone pillar in the open air. It was not possible, with 1/60 of the light of the Rosse mirror, to see so well; but it was easy to represent far better what one saw, with a conveniently placed board to hold the drawing-paper, a well-arranged light, and no necessity of changing position. I made in this manner the drawing of Gassendi which is marked No. 2.