5i8 THE POPULAR SCIENCE MONTHLY. 



dark-blue of the sky in which it floats, the painted revelation of the 

 wonders of a sister world. Plainer than words, this colored image 

 tells the story of an activity of tempests, and bubbling caldrons of 

 fire long since burned out ; of oceans evaporated and drawn into the 

 deepest depths of a dying world of present silence and empty deso- 

 lation ! 



Encouraged by the approval of famous scientists, who have exam- 

 ined and testified to the correctness and beauty of this first phase of 

 the moon, Mr. Harrison has completed a second phase, and is at work 

 on the remaining pictures, which are in various stages of progression. 



Among the prominent features represented as seen on the tele- 

 scopic moon at the first quarter may be mentioned the Mare Crisium, 

 one of the darkest of all the regularly bordered mares or dark plains. 

 Crisium shows a surface of a gray tint tinged with green. At times 

 it is curiously dotted and streaked with light. The floor is traversed 

 by ridges crossing each other and throwing up small peaks. At the 

 first quarter appears Messier, on the terminator of the three-days-old 

 crescent. Messier is a fine crater-plain, nine miles in diameter, inclosed 

 by a bright mountain- wall. To the southeast rise the walls of Catha- 

 rina, in some places reaching a height of sixteen thousand feet above 

 the interior plain, which, under the highest magnifying power, shows 

 a surface broken up into mounds, ridges, hills, and craterlets. 



Lying to the northwest appears the Mare Fcecunditatis, the largest 

 of the western mares or sea-beds, covering an area of one hundred and 

 sixty thousand square miles, and penetrating, in bay-like indentations, 

 into the mountain-ranges southward. Mare Tranquillitatis and Sereni- 

 tatis, the latter one of the most prominent gray plains seen at the first 

 quarter. The entire central portion of this mare shows a decided 

 light-green tinge. 



At the last quarter the most striking feature is Copernicus, the 

 grandest ring-plain on the northern quadrant, and one of the most in- 

 structive. Its vast walls rise nearly twelve thousand feet above the 

 level of the plateau, showing fifty magnificent peaks that shine at cer- 

 tain seasons like a crown of pearls on a radiant background. The cen- 

 tral cones attain a height of nearly three thousand feet. On the inner 

 side the walls fall abruptly in terraces to the floor, while, without, they 

 slope gradually, and are broken into confused ridges, spreading away 

 from their bases into hill and mountain chains. 



Aristarchus, a brilliant ring-plain, is also visible at the last quarter ; 

 its broad, terraced walls rise twenty-six hundred feet above the moon's 

 surface, and seven thousand five hundred above its own interior floor, 

 nearly in the center of which stand two peaks and a small crater, the 

 central peak being the most brilliant point visible on the moon. Among 

 the bays, so called, seen on this quarter, is the Sinus Iridum, a dark, 

 semicircular level, bordered by the magnificent cliffs of one of the 

 most stupendous highlands of the moon, whose crest sends up at cer- 



