1826.] Telescopical Observations on the Moon, 341 



be examined with a good and powerful telescope, the appear- 

 ances here noticed can scarcely fail to convey the idea, that the 

 earth, viewed from a great distance, would present the same 

 general aspect. If an observer stand about half way up a very 

 high cliff, whose shadow is projected upon the sea, he will be 

 sheltered from the sun's rays : the water being clear, the bed of 

 the sea will be illuminated, but less so than the neighbouring 

 land ; the shadows of elevated places have the soft appearance 

 observed in some parts of the moon ; whilst the sea appears 

 dark. There is no doubt, or at least I have none, from the 

 observations I have made, but that the ridges and other sup- 

 posed submarine objects are sometimes more distinct and more 

 conspicuous than at others, the air being quite clear, and the 

 moon at the same age : this I have especially noticed in Palus 

 Moeotis, a part of the moon well adapted to observations of this 

 sort. As an additional confirmation, the surface of each of the 

 dark parts must be smooth and spherical ; else how can the 

 terminator appear smooth and elliptical in passing over them? 



There are parts of the moon which have the appearance of 

 rivers and small lakes ; rivers, if there be any, cannot be traced 

 through their whole length ; because, at least on the earth, at a 

 great distance from the sea, their breadth is too small to be seen 

 at so great a distance as that of the moon. I am aware that 

 some of your readers may be inclined to regard this statement 

 as visionary ; I only beg such to examine Palus Moeotis with a 

 large telescope, if possible, one which bears a power of 400 or 

 500, with sufiicient light ; the telescope should be so firmly 

 mounted as not to be affected by tremors, and the air should be 

 clear; the best time is when the moon is about eight or nine 

 days old ; on the north margin will bie found a conspicuous 

 narrow hne, running nearly parallel with a small part of the 

 north-west, the whole of the north, and part of the north-east 

 boundary of Mceotis, and joined to it by four similar lines which 

 increase in breadth as they approach it ; to the east is another 

 such line, whose south extremity divides into two short branches, 

 one of which touches a mountain which stands at the point 

 where Palus By ces joins L. Corocondametis ; on the south-west, 

 from the end of the projection joining Pr, Agarum, another 

 rises, joined by a second, a little to the south; after the junc- 

 tion, the branch takes a direction little west of the south; its 

 extremity is divided into four branches which run towards 

 Paludes. I had a very distinct view of these parts, June 13, 

 1826, as well as at other times before and since ; they are seen 

 to great advantage with the six inch reflector, and powers from 

 200 to 400, and when the atmosphere is in a very fine state 

 with 800 : I have seen them very well with my 40 feet aerial, 

 power 200. A drawing will be sent for insertion in the Annals, 

 when 1 shall have had opportunity to make observations during 



