60 Mare Vaporum and the Lunar Clefts. 



as 26 and 27 in our little Map; the remarkable crater M anilius 

 (24) lies only a little below the area represented ; for telescopic 

 search these features, previously recognized from their posi- 

 tion relative to the M. Serenitatis and the Apennines, will 

 always be sure guides. The cleft passing through Hyginus is 

 the first described by B. and M. It is conspicuous enough to 

 be seen in a good telescope with a power of 40, and under 

 almost any illumination. Its commencement, from the N.E., 

 is at a long, low hill, and here it appears almost as a flat valley, 

 nearly 1| mile wide, but after a length of 9 miles it becomes 

 narrowed to a breadth of 1300 — 1500 yards, with such steep- 

 ness and depth that, in one instance, B. and M. distinctly 

 perceived the delicate black line of shadow on one side running 

 parallel with the brightly-illuminated opposite bank. In this 

 part of its course, which is through level ground, it encounters 

 four little craters, the second of which is 3200 yards, or nearly 

 2 miles across; the others 2000 to 2500 yards. After running 

 about 50 miles it reaches the larger crater, Hyginus. But what 

 happens to it there, and in its further progress, must be 

 reserved to a future opportunity. 



OCCULTATIONS. 



Aug. 2nd, 22h. 34m. to 23h. 16m., or in common reckoning, 

 3rd, lOh. 34m. to llh. 16m. a.m. the planet Mars. This 

 obviously requires a large aperture and equatoreal mounting. 

 — 15th, e 1 Aquarii, 6 mag. llh. 54m. to 12h. 52m. — 16th, 

 A, Aquarii, 4 mag. 7h. 50m. to 8h. 51m. 



