an astronomer better
acquainted with the human heart, met with a success that has lasted to
the present day.

This was Father Riccioli, a Jesuit, and (1598-1671) a contemporary of
Hevelius. In his _Astronomia Reformata_, (1665), he published a rough
and incorrect map of the Moon, compiled from observations made by
Grimaldi of Ferrara; but in designating the mountains, he named them
after eminent astronomers, and this idea of his has been carefully
carried out by map makers of later times.

A third map of the Moon was published at Rome in 1666 by Dominico
Cassini of Nice (1625-1712), the famous discoverer of Saturn's
satellites. Though somewhat incorrect regarding measurements, it was
superior to Riccioli's in execution, and for a long time it was
considered a standard work. Copies of this map are still to be found,
but Cassini's original copper-plate, preserved for a long time at the
_Imprimerie Royale_ in Paris, was at last sold to a brazier, by no less
a personage than the Director of the establishment himself, who,
according to Arago, wanted to get rid of what he considered useless
lumber!

La Hire (1640-1718), professor of astronomy in the _College de France_,
and an accomplished draughtsman, drew a map of the Moon which was
thirteen feet in diameter. This map could be seen long afterwards in the
library of St. Genevieve, Paris, but it was never engraved.

About 1760, Mayer, a famous German astronomer and the director of the
observatory of Goettingen, began the publication of a magnificent map of
the Moon, drawn after lunar measurements all rigorously verified by
himself. Unfortunately his death in 1762 interrupted a work which would
have surpassed in accuracy every previous effort of the kind.

Next appears Schroeter of Erfurt (1745-1816), a fine observer (he first
discovered the Lunar _Rills_), but a poor draughtsman: his maps are
therefore of little value. Lohrman of Dresden published in 1838 an
excellent map of the Moon, 15 inches in diameter, accompanied by
descriptive text and several charts of particular portions on a larger
scale.

But this and all other maps were thrown completely into the shade by
Beer and Maedler's famous _Mappa Selenographica_, so often alluded to in
the course of this work. This map, projected orthographically--that is,
one in which all the rays proceeding from the surface to the eye are
supposed to be parallel to each other--gives a reproduction of the lunar
disc exactly as it