rilliantly white. The polar cap had become enlarged in the interim,
apparently through a wide-spreading snow-fall, by the annexation of a
territory equal to that of the United States. The season was towards the
close of winter in Mars. Never until then had the process of glacial
extension been actually (it might be said) superintended in that distant
globe.

Mars was gratuitously supplied with a pair of satellites long before he
was found actually to possess them. Kepler interpreted Galileo's anagram
of the "triple" Saturn in this sense; they were perceived by Micromegas
on his long voyage through space; and the Laputan astronomers had even
arrived at a knowledge, curiously accurate under the circumstances, of
their distances and periods. But terrestrial observers could see nothing
of them until the night of August 11, 1877. The planet was then within
one month of its second nearest approach to the earth during the last
century; and in 1845 the Washington 26-inch refractor was not in
existence.[1009] Professor Asaph Hall, accordingly, determined to turn
the conjecture to account for an exhaustive inquiry into the
surroundings of Mars. Keeping his glaring disc just outside the field of
view, a minute attendant speck of light was "glimpsed" August 11. Bad
weather, however, intervened, and it was not until the 16th that it was
ascertained to be what it appeared--a satellite. On the following
evening a second, still nearer to the primary, was discovered, which, by
the bewildering rapidity of its passages hither and thither, produced at
first the effect of quite a crowd of little moons.[1010]

Both these delicate objects have since been repeatedly observed, both in
Europe and America, even with comparatively small instruments. At the
opposition of 1884, indeed, the distance of the planet was too great to
permit of the detection of both elsewhere than at Washington. But the
Lick equatoreal showed them, July 18, 1888, when their brightness was
only 0.12 its amount at the time of their discovery; so that they can
now be followed for a considerable time before and after the least
favourable oppositions.

The names chosen for them were taken from the Iliad, where "Deimos" and
"Phobos" (Fear and Panic) are represented as the companions in battle of
Ares. In several respects, they are interesting and remarkable bodies.
As to size, they may be said to stand midway between meteorites and
satellites. From careful photometric measure