278 The Lunar Eratosthenes and Copernicus. 



not deviate much from a circular form, bears a comparatively 

 narrow crest, very brilliant, even to 8° and 9°, in full illumina- 

 tion ; under especially favourable conditions it appears like a 

 string of pearls, and on one occasion B. and M. believed that 

 they counted upwards of 50 of these probably very minute 

 summits. The highest point on the W. attains 11,300ft., on 

 the E. it is only about 300ft. lower, as measured from the 

 depth below. Schr. had given 9,600ft. The whole breadth 

 of the wall is considerable, and its structure is very complex ; 

 nowhere, perhaps, on the lunar surface is the terrace-form more 

 obvious, though some of the ridges can hardly come under that 

 designation, being divided by deep gorges from the central 

 crest. This circumstance, and the serpentine form of some of 

 them, had been noticed by Schr., and beautifully represented 

 by Sir J. Herschel in his " Outlines of Astronomy," where the 

 portrait, though anonymous, may be easily recognized. Between 

 the innumerable ridges which break up the inner slope on the 

 1ST., Schr/s 27ft. reflector showed him about 20 minute hills. 

 He remarks that if the interior were inhabited by creatures 

 like ourselves, their journeys would be attended with much 

 difficulty ; ' ' but Omnipotence knows no bounds in the manifold 

 organization of its creatures." There is a considerable central 

 mass, consisting of six separate summits, of which two overtop 

 the rest; the small one between them, discovered by Schr., 

 could not be found by him upon a subsequent occasion, but 

 appears in the drawing of H. 



Schmidt, who considers this ring as combining all the 

 characters of the class to which it belongs, will hardly be 

 contradicted when he says that ' ' careful studies of this incom- 

 parably beautiful and magnificent image alone fully counter- 

 poise those of a hundred other craters." On E. he found the 

 inclination of the crest and some of the terraces amounting in 

 places to 50° and even 60° — a fearfully rapid acclivity — which 

 towards the foot sinks down to 10° and 2°; and on this side he 

 considered it about 12,500ft. high ; the W. peak is some 

 1000ft. loftier still, rising nearly 7000ft. above the convex ter- 

 races at its base, themselves ranging 6000ft. above the interior. 

 The latter, he says, is probably concave ; the two principal 

 central hills attain, E. 2400ft., W. 2000ft. Even these must 

 require a considerable climb, and command a magnificent view 

 of the surrounding rampart, at a distance of twenty-eight miles 

 on every side. The same observer remarks the absence of 

 minute outbursts on and within the wall, and, also, the gene- 

 ral raising of the ground for a long distance — no less than one 

 hundred miles from E. to W., which may bo dotocled when 

 Copernicus lies 5° to 10° from the terminator— a very interest- 

 ing fact, as showing the wide outspreading and probably deep 



