MERCURY.
The planet enjoying the distinction of being the nearest to the center of our system is too near the “dazzling brightness” to permit our finding out much about its physical constitution. We suppose, but do not know, that it revolves on its axis. We guess that it has satellites, but no one is certain that he ever saw one of them. We used to think it must be a very warm planet; but now we think it might perhaps be a moderately comfortable place for a mortal to reside. The fact is, what we do not know about it is much more than what we do know; and what we know about it for this month is nearly as follows: On the 1st, 15th, 25th and 30th it will rise after the sun, and will not be visible to the unaided eye; but on the same dates it will set at 6:32, 7:03, 8:37 and 8:35 p. m., respectively, and can therefore be easily seen after sunset from the 20th to the end of the month by anybody who will take the pains to look for it—that is, within the latitude in which most of our readers live. It reaches its most easterly limit (20° 32′) at 9:00 p. m. on the evening of the 25th, and approaches so much nearer to us during the month as to cause its diameter to appear nearly twice as large—that is, to increase from 5″ to 9″. On the 21st at 2:00 a. m. it will be 4° 20′ north of Neptune, and on the 26th at 5:55 p. m., 5° 47′ north of the moon.