It has one peculiarity; it twinkles like a star. In this respect it
differs from all the other planets. Its nearness to the sun has led
some astronomers to believe that the temperature is very uneven, that
“every six weeks on an average there is a change of temperature nearly
equal to the difference between frozen quicksilver and melted lead.”
But later discoveries indicate that temperature dependent on the sun’s
rays is influenced much more by the media through which the rays pass,
or by which they are absorbed, than the proximity of the sun; and hence
Professor Langley argues that Mercury might be a globe on which people
like ourselves could have the proper degree of heat to sustain life. Our
calendar for Mercury for this month is as follows: On the 1st, it rises
at 5:50 a. m.; on 15th, at 5:54 a. m.; and on 31st, at 5:57 a. m. On the
same dates it sets as follows: 3:52, 4:52 and 6:25 p. m. On the 30th it
will be in superior conjunction with the sun, that is, in a line with
the sun and earth, but having the sun between it and the earth. Up to
this last date it will be morning star; after that, evening star. On the
26th, at 9:11 p. m., it will be 3° 25′ south of the moon. The only other
inferior planet with which we are acquainted is called Venus.