and 7 tenth-parts of a second. So that Mars requires 41 minutes 18
seconds and 6-tenths of a second longer to turn his small body once
round than our earth requires to turn round her much larger body. The
common day of Mars is, however, only about 39 minutes longer than our
common day.

Mars has a long year, taking no less than 687 of our days to complete
his circuit round the sun, so that his year lasts only about one month
and a half less than two of ours.

[Illustration: APPEARANCE OF MARS, 1852, MARCH 23, 5 H. 45 M.,
Greenwich Mean Time. Power of Telescope, 358; 6-1/3 inch object-glass]

[Illustration: APPEARANCE OF MARS, 1852, FEBRUARY 3, 6 H. 50 M.,
Greenwich Mean Time. Power of Telescope, 242 and 358 on 6-1/3 inch
object-glass.]

[Illustration: APPEARANCE OF MARS, 1860, JULY 6, 11 H. 33 M.,
Greenwich Mean Time. Power of Telescope, 201; 8-1/4 inch object-glass.
Planet very low, yet pretty distinct.]

Like the earth, Mars has seasons, for his polar axis, like that of
the earth, is aslant, and at one part of his year brings his northern
regions more fully into sunlight, at which time summer prevails there
and winter in his southern regions; while at the opposite part of his
year his southern regions are turned more fully sunward and have their
summer, while winter prevails over his northern regions.

Around his poles, as around the earth's, there are great masses of
ice, insomuch that it is very doubtful whether any inhabitants of Mars