anilius, Ptolemaeus, and Guerike.
4 1/2 deg. Surface round Aristillus, Sinus Medii.
5 deg. Walls of Arago, Landsberg, and Bullialdus. Surface round
Kepler and Archimedes.
5 1/2 deg. Walls of Picard and Timocharis. Rays from Copernicus.
6 deg. Walls of Macrobius, Kant, Bessel, Mosting, and Flamsteed.
6 1/2 deg. Walls of Langrenus, Theaetetus, and Lahire.
7 deg. Theon, Ariadaeus, Bode B, Wichmann, and Kepler.
7 1/2 deg. Ukert, Hortensius, Euclides.
8 deg. Walls of Godin, Bode, and Copernicus.
8 1/2 deg. Walls of Proclus, Bode A, and Hipparchus c.
9 deg. Censorinus, Dionysius, Mosting A, and Mersenius B and c.
9 1/2 deg. Interior of Aristarchus, La Peyrouse DELTA.
10 deg. Central peak of Aristarchus.

TEMPERATURE OF THE MOON'S SURFACE.--Till the subject was undertaken some
years ago by Lord Rosse, no approach was made to a satisfactory
determination of the surface temperature of the moon. From his
experiments he inferred that the maximum temperature attained, at or near
the equator, about three days after full moon, does not exceed 200 deg.
C., while the minimum is not much under zero C. Subsequent experiments,
however, both by himself and Professor Langley, render these results more
than doubtful, without it is admitted that the moon has an atmospheric
covering. Langley's results make it probable that the temperature never
rises above the freezing-point of water, and that at the end of the
prolonged lunar night of fourteen days it must sink to at least 200 deg.
below zero. Mr. F.W. Verey of the Alleghany Observatory has recently
conducted, by means of the bolometer, similar researches as to the
distribution of the moon's heat and its variation with the phase, by
which he has deduced the varying radiation from the surface in different
localities of the moon under various solar altitudes.

LUNAR OBSERVATION.--In observing the moon, we enjoy an advantage of which
we cannot boast when most other planetary bodies are scrutinised; for we
see the actual surface of another world undimmed by palpable clouds or
exhalations, except such as exist in the air above us; and can gaze on
the marvellous variety of objects it presents much as we contemplate a
relief map of our own globe. But inasmuch as the manifold details of the
relief map require to be placed in a certain light to be seen to the best
advantage, so the ring-mountains, rugged highlands, and wide-extending
plains of our satellite, as the