It is somewhat remarkable that the one celestial body which Herschel neglected was our satellite, the Moon; and it is also remarkable that the Moon was for many years the chief object of study of his contemporary astronomer, _Johann Hieronymus Schröter_ (1745-1816). Born at Erfurt, near Hanover, on August 30, 1745, Johann Hieronymus Schröter was originally intended for the study of law, for which he was sent to the University of Göttingen. At the same time he studied mathematics, and particularly astronomy, under the mathematician, Kaestner of Göttingen. Deeply interested in music, he became acquainted with the Herschel family, and, inspired by William Herschel’s example, determined to study the heavens. In 1779 he became the possessor of a small achromatic refractor, and commenced to observe the Sun and Moon. In 1778 he entered the legal profession at Hanover, and four years later he was appointed “oberamtmann” or Chief Magistrate of Lilienthal—“the Vale of Lilies”—in the Duchy of Bremen. At Lilienthal Schröter erected a small observatory, and acquired in 1785 one of Herschel’s 7-foot reflectors. In 1792 the astronomer superintended the construction of a 13-foot reflector, made by Schrader of Kiel, who transferred his workshop to Lilienthal. With these instruments the great work of Schröter was accomplished. Schröter directed his powers of observation to the study of the Moon. He originated the study of the surface of the Moon, and founded the branch of astronomy known as selenography, or the study of the Moon’s surface. The foundations of this branch were laid in 1791 with the publication of Schröter’s ‘Seleno-topographische Fragmente’. The astronomer determined to make a comparative study of the surface of our satellite, and before 1801 discovered eleven “rills” or clefts on the Moon’s surface, and recognised a large number of craters. He likewise believed that he had seen a lunar atmosphere, an observation of which was made by him in February 1792. Schröter seems never to have doubted what Herschel and his contemporaries believed—that the Moon was a living world with volcanoes in active eruption, surrounded by an atmosphere, and inhabited by beings like ourselves. Unfortunately, Schröter was not good at making drawings of what he saw; nevertheless, he accomplished a vast amount of work. In the little observatory at Lilienthal the foundations were laid of the comparative study of the surface of the Moon.