94 H. C. RUSSELL. 



or at least published before. In one of these the well-known 

 lunar crater : ' Copernicus," appears more than half an inch in 

 diameter, and a mass of detail is revealed in and about the crater 

 altogether new in photographs of the Moon. 



Another shows " Eratosthenes " and the Apennine Range of 

 lunar mountains, with the very remarkable elevated plateau which 

 extends away from them towards the south, and forms the divide 

 between the Bay of Tides and the Sea of Vapours. 



I will not take up your time in describing the details, you can 

 see them in the photographs in much less time than it would take 

 to describe them, and certainly much better. I may however 

 mention, that one of those dark markings which can be seen on 

 the moon's surface is very conspicuous here ; it looks something 

 like a shadow, and is bounded by roughly parallel lines and straight 

 sides, there is however nothing to cause such a shadow, and from 

 the fact that it is there in all the varying lights, as the sun rises 

 over these hills and vallies, it is evident that it is a peculiarity of 

 the surface of the moon, which from some cause does not in this 

 part reflect so much light as in other parts. The dark space is about 

 thirty-five miles wide and one hundred and twenty miles long, and 

 stretches not only right across the great spur of the Apennines 

 referred to above, but also over a great part of the Sea of 

 Vapours. 



Another photograph includes about half the Sea of Showers 

 with the craters "Eratosthenes" and "Plato," as conspicuous 

 objects. On this sea much detail of surface is depicted, the 

 undulations of the surface, ' little hills &c.,' being very conspicuous. 



Still another photograph takes in perhaps the most rugged part 

 of the moon's surface. The most conspicuous crater here by its 

 position on the terminator as well as by its actual size is " Clavius," 

 one hundred and forty-two miles in diameter, its towering moun- 

 tainous ring running up in places to eighteen thousand feet. 



This object is beautifully shown, the curious string of smaller 

 craters which stretch across the floor being very clearly denned ; 



