Lunar Sketches. 448 



centre of that line, where they form a nearly equilateral 

 triangle, with one angle JN". The N.W. side of this area is 

 bordered by a long dark valley, extending S.W. 37 miles, 

 and dividing it from a system of small parallel chains, whose 

 highest summit, £, attains about 2600 feet. This mountain, 

 already mentioned in p. 871 of our last number, must be looked 

 for just S.S.W. of the little but conspicuous crater c, the 

 only one at once S.W. of Copernicus aud S.E. of Stadius ; it 

 must also stand very near the ISLE, end of the bright streak 

 which divides Rhceticus in the Full Moon (p. 216, antea). Of 

 the parallel ridges they say 3 ec these mountains are very dark, 

 and here, in the Full Moon, a large blackish spot shows itself/' 

 in which they are unconsciously describing the W. part of 

 their vainly-sought Rhceticus of Riccioli, the other portion 

 seeming to be the "long dark valley" just described. There 

 appears little doubt that in this parallelism may be found the 

 ' rampart-work " of Grruithuisen, the regular arrangement of 

 which would probably repay a search 3 at the other end of the 

 streak dividing Rhceticus, and consequently near the S.W. 

 angle of their hill-triangle to the E. of it, they place a little 

 summit e. They_ remark that while the dark mountains con- 

 tinue so in full illumination, the triangle is brighter, 3° to 3| ° 

 of light, and e has " exclusively a brilliancy of 7°, which it 

 does not lose even in the neighbourhood of the terminator, an 

 anomaly which is so much the more remarkable because it 

 otherwise is not distinguished, either through form or elevation, 

 from the rest, several of which overtop it." I regret that I 

 did not notice this curious passage in time to compare it with 

 the existing state of reflective power, but I have no recollection 

 of such a spot when I was identifying Rhceticus, the notices of 

 which are strangely scattered about in B. & M., and it must 

 be left as an interesting subject of research for some of our 

 readers. 



E. of Gambart is a bright (8°) and conspicuous little 

 crater A. 



Reinhold (our 31) is a crater 31 miles in diameter, with 

 strong terraces and a central hill at the N. end of a little ridge. 

 The W. side of the ring is 9400ft., the E. 7000ft. above the 

 interior. Schr. gives the former measure 8700ft., and makes 

 the external height of the E. wall 1900ft. A mountain-ridge 

 connects it with Copernicus, bending, as it were, round both 

 the rings. 



N.E. of Copernicus, we find a lofty tract which B. and M. 

 call Mt. Oarpathus, extending with its dependencies from E. 

 to W. 280 miles. It includes Gay Lussac, a double crater 

 already described in our p. 370 : the smaller basin A is deeper, 

 steeper, and brighter than its broader, and apparently more 



