elative to
the similarity of all these points, their great brightness, and their
remarkable colour.

Yet is not red the usual colour of the moon when eclipsed, and when it
has not entirely disappeared? Could the solar rays reaching our
satellite by the effect of refraction, and after an absorption
experienced in the lowest strata of the terrestrial atmosphere, receive
another tint? Are there not in the moon, when freely illuminated, and
opposite to the sun, from one to two hundred little points, remarkable
by the brightness of their light? Would it be possible for those little
points not to be also distinguishable in the moon, when it receives only
the portion of solar light which is refracted and coloured by our
atmosphere?

Herschel was more successful in his remarks on the absence of a lunar
atmosphere. During the solar eclipse of the 5th September, 1793, the
illustrious astronomer particularly directed his attention to the shape
of the acute horn resulting from the intersection of the limbs of the
moon and of the sun. He deduced from his observation that if towards the
point of the horn there had been a deviation of only one second,
occasioned by the refraction of the solar light in the lunar atmosphere,
it would not have escaped him.

Herschel made the planets the object of numerous researches. Mercury was
the one with which he least occupied himself; he found its disk
perfectly round on observing it during its projection, that is to say,
in astronomical language, during its transit over the sun on the 9th of
November, 1802. He sought to determine the time of the rotation of Venus
since the year 1777. He published two memoirs relative to Mars, the one
in 1781, the other in 1784, and the discovery of its being flattened at
the poles we owe to him. After the discovery of the small planets,
Ceres, Pallas, Juno, and Vesta, by Piazzi, Olbers, and Harding, Herschel
applied himself to measuring their angular diameter. He concluded from
his researches that those four new bodies did not deserve the name of
planets, and he proposed to call them asteroids. This epithet was
subsequently adopted; though bitterly criticized by a historian of the
Royal Society of London, Dr. Thomson, who went so far as to suppose
that the learned astronomer "had wished to deprive the first observers
of those bodies, of all idea of rating themselves as high as him
(Herschel) in the scale of astronomical discoverers." I should require
nothing f