ASTRONOMY WITH AN OPERA-GLASS. 485 



sometimes detected in its central parts. It deepens toward the middle. 

 Three quarters of its shore-line are bordered by high mountains, and 

 many isolated elevations and peaks are scattered over its surface. In 

 looking at these dried-up seas of the moon, one is forcibly reminded 

 of the undulating and in some places mountainous character of terres- 

 trial sea-bottoms as shown by soundings and the existence of small 

 islands in the deep sea, like the Bermudas, the Azores, and St. Helena. 

 The Sea of Serenity is divided nearly through the center by a narrow, 

 bright streak, apparently starting from the crater-mountain Menelaus 

 (36 in the map), but really taking its rise at Tycho far in the south. 

 This curious streak can be readily detected even with a small opera- 

 glass. Just what it is no one is prepared to say, and so the author of 

 the " Moon Hoax " was fairly entitled to take advantage of the ro- 

 mancer's license, and declare that "its edge throughout its whole 

 length of three hundred and forty miles is an acute angle of solid 

 quartz-crystal, brilliant as a piece of Derbyshire spar just brought 

 from the mine, and containing scarcely a fracture or a chasm from end 

 to end ! " Along the southern shore, on either side of Menelaus, ex- 

 tends the high range of the Hsemus Mountains. South and southeast 

 of the Sea of Serenity are the Sea of Vapors (L)*, the Central Gulf 

 (M), and the Gulf of Heats (N). The observer will notice at full 

 moon three or four curious dark spots in the region occupied by these 

 flat expanses. On the north and northwest of the Sea of Serenity are 

 the Lake of Death (D), and the Lake of Dreams (E), chiefly remark- 

 able for their names. 



The Sea of Showers (O) is a very interesting region, not only in 

 itself, but on account of its surroundings. Its level is very much 

 broken by low, winding ridges, and it is variegated by numerous light 

 streaks. At its western end it blends into the Marsh of Mists (I) and 

 the Marsh of Putrefaction (K). On its northeast border is the cele- 

 brated Sinus Iridum, or Bay of Rainbows (P), upon which stenog- 

 raphers have exhausted the adjectives of admiration. The bay is 

 semicircular in form, one hundred and thirty-five miles long and 

 eighty-four miles broad. Its surface is dark and level. At either end 

 a splendid cape extends into the Sea of Showers, the eastern one being 

 called Cape Heraclides, and the western Cape Laplace. They are 

 both crowned by high peaks. Along the whole shore of the bay runs 

 a chain of gigantic mountains forming the southern border of a wild 

 and lofty plateau, called the Sinus Iridum Highlands. Of course, a 

 telescope is required to see the details of this " most magnificent of 

 all lunar landscapes," and yet much can be done with a good field- 

 glass. With such an instrument I have seen the capes at the ends of 

 the bay projecting boldly into the dark, level expanse surrounding 

 them, and the high lights of the bordering mountains sharply con- 



* The letter L has accidentally been misplaced in the map. It should be on the 

 dark expanse below its present place. 



