The first of these was Galileo. His slight telescope magnified only thirty times, still, in the spots flecking the lunar surface, like the eyes checkering a peacock's tail, he was the first to discover mountains and even to measure their heights. These, considering the difficulties under which he labored, were wonderfully accurate, but unfortunately he made no map embodying his observations. A few years afterwards, Hevel of Dantzic, (1611-1688) a Polish astronomer--more generally known as Hevelius, his works being all written in Latin--undertook to correct Galileo's measurements. But as his method could be strictly accurate only twice a month--the periods of the first and second quadratures--his rectifications could be hardly called successful. Still it is to the labors of this eminent astronomer, carried on uninterruptedly for fifty years in his own observatory, that we owe the first map of the Moon. It was published in 1647 under the name of _Selenographia_. He represented the circular mountains by open spots somewhat round in shape, and by shaded figures he indicated the vast plains, or, as he called them, the _seas_, that occupied so much of her surface. These he designated by names taken from our Earth. His map shows you a _Mount Sinai_ the midst of an _Arabia_, an _AEtna_ in the centre of a _Sicily_, _Alps_, _Apennines_, _Carpathians_, a _Mediterranean_, a _Palus Maeolis_, a _Pontus Euxinus_, and a _Caspian Sea_. But these names seem to have been given capriciously and at random, for they never recall any resemblance existing between themselves and their namesakes on our globe. In the wide open spot, for instance, connected on the south with vast continents and terminating in a point, it would be no easy matter to recognize the reversed image of the _Indian Peninsula_, the _Bay of Bengal_, and _Cochin China_. Naturally, therefore, these names were nearly all soon dropped; but another system of nomenclature, proposed by 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.