the Melbourne Great Telescope. 67 



tive ranges rise terrace-like from the floorto the summit of this 

 ring. The briglit rays (of which Copernicus forms a centre) 

 are visible for hundreds of miles in every direction up to the 

 very edge of terminator, where, although any diflference of 

 level of 10 feet would produce a visible shadow, these rays 

 still neither receive nor throw a shadow. Some parts of 

 them appear dislocated by the crossing of ranges, &c., over 

 their path. They seem evidently dykes — selenologically 

 speaking — of a more reflective kind of rock or rock of a 

 lighter color than the country through which they pass, and 

 which they have ruptured and supplanted. In one place a 

 ray passes completely over the side of a crater-ring, yet 

 conforms itself to the general surface of the crater ; it 

 intersects, indicating apparently that the surface must have 

 been still in a plastic state after the date of Copernicus, and 

 the radiating streaks from it, and at the time of the formation 

 of the latter crater-ring. 



Copernicus. — 5th Dec, moon nearly full — Copernicus 

 under full illumination shows terraces of varying brilliancy 

 arguing different dates of formation. The bright rays not 

 more conspicuous than when on edge of terminator, but 

 having a more cloudy look — four central peaks of same 

 appearance still. 



Maria. — Swept the Telescope over the different plains, 

 and was unexpectedly struck with the green tint in many 

 places pervading them, apart from the uncorrected 

 chromatism of the eyepiece (power 255). 



Aristarchits. — The crater Aristarchus is about 100 miles 

 from terminator. It appears many times more bright than the 

 brightest object elsewhei'e — a painful brilliancy which gave, 

 unlike all other lunar craters, the impression of heat as well as 

 liofht. The shadow from the western wall of the ring is almost 

 obJitei'ated by the apparently inherent light of the interior. 

 The steep central hill appears to-night to have a minute 

 crater on its summit, very apparent at times, at others dim 

 and vapoury-looking. A range visible beyond Aristarchus to 

 the N.E., stretching as it were across the horizon 50 to 70 

 miles distant, and round the two terminating bluffs of this 

 range extended a vapourous-looking film, which encircled, also, 

 Aristarchus. at a distance of, say 30 miles. Within this girdle 

 of haze, Aristarchus, and the range, Herodotus, &c., 

 appeared sharply defined — sharply comparative!}^ speaking 

 only, for these objects are all near the limb, and in the Great 

 Telescope all objects near the moon's limb appear loss distinct 



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