80 SCENERY OF THE HEAVENS. 



and being at the full, her appearance was extremely delightful. It was the conclusion 

 of the holidays, and many of the people were enjoying the delicious coolness of a serene 

 night, and resting from the laborious exertions of the day; but when the moon became 

 gradually obscured, fear overcame every one. As the eclipse increased, they became 

 more terrified. All ran in great distress to inform their sovereign of the circumstance, 

 for there was not a single cloud to cause so deep a shadow, and they could not compre- 

 hend the nature or meaning of an eclipse. Groups of men were blowing on trumpets, 

 which produced a harsh and discordant sound ; some were employed in beating old 

 drums ; others again were blowing on bullocks' horns. The diminished light, when 

 the eclipse was complete, was just sufficient to enable us to distinguish the various 

 groups of people, and contributed in no small degree to render the scene still more 

 imposing. If an European, a stranger to Africa, had been placed on a sudden in the 

 midst of the terror-struck people, he would have imagined himself among a legion of 

 demons, holding a revel over a fallen spirit." 



Besides the orbital motipn, there is another lunar movement, not so obvious, but plainly 

 demonstrable. It is a well known fact, that the same portion of the moon's surface, or 

 nearly so, is always turned towards the earth. It necessarily follows, that during each 

 revolution she must rotate upon herself, and accomplish one rotation in the time of one 

 revolution. If we suppose an individual to walk round a tree, and to keep his face 

 turned towards it, he will see completely round the horizon during his circuit, and will of 

 course turn round upon himself. The alterations are slight as to the face which the 

 moon presents to us in all her revolutions. On the eastern and western sides, and also 

 on the northern and southern edges, small portions of disk alternately appear and 

 disappear, as though the lunar globe oscillated and swung to and fro in space ; and hence 

 these appearances are termed librations, from libra, a balance, the former being in 

 latitude, and the latter in longitude. There is, however, no real oscillation, but the 

 orbital motion being irregular, while that on the axis is uniform, the effect is, alternately 

 to extend and diminish the sides of the exhibited surface, as though an actual vibration 

 of the whole body took place. These variations do not affect the correctness of the 

 general statement, that the moon always shows the same face to us ; and this is the con- 

 sequence of the coincidence between the time in which she moves round the earth and 

 rotates upon her axis. Here we have a law to which none of the primary bodies in the 

 system are subject, though it is probable that all the secondary bodies are. There is the 

 same correspondence between the period occupied by the satellites of Jupiter in revolving 

 round that planet and rotating upon their axes. The reasons of the law are at present 

 inscrutable. It is one of those mechanical arrangements, the design of which we have 

 yet to apprehend. 



It will be seen from the preceding statements, that though the moon is our near 

 neighbour, and has been for ages a faithful companion orb, the acquaintance is very 

 partial and reserved. Almost one half of the satellite is perpetually turned from the 

 earth, and to those regions that are thus concealed from us the earth is never visible. 

 The lunarians, if such there are, inhabiting the districts beyond and opposite to the 

 exhibited side of the moon, never catch a glimpse of the earth, unless they travel into 

 the hemisphere presented. A parallel case on our globe would be, for the moon never to 

 appear in the nocturnal sky of Europe and Africa, and for an Englishman to know 

 nothing of the luminary, unless he should travel towards the heart of Asia, or land upon 

 the shores of America. To an inhabitant of the moon on the border of her visible disk, 

 the earth will appear in the horizon. One about the centre of the visible disk will have 

 the earth near his zenith, but through the wide extent beyond the border, embracing 

 nearly half the lunar surface, the earth is never seen. The hemispheres of the moon 



