MOON 



Aspect of the known face of the moon, showing the " seas," 

 lakes, and craters. The chief craters are numbered as 

 follows : 1. Newton. 2. Short. 3. Horetus. 4. Clavius. 5. 

 Scheiner. 6. Bacon. 7. Maginua. 8. Longomontanus. 9. 

 Schiller. 10. Schickard. 11. Wllhelm I. 12 Tycho. 13. 

 Btoeffler. 14. Hainzel. 15. Walter. 16. Biccius, 17. Furmerius, 

 18. Piccolomint. 19. Pitatus. 20. Purbach. 21. Sacrobosco. 

 Z2. Fracastorius. 23. Petavius. 24. Arzachael. 25. Thebit, 

 26. Hlppalus. 27. Gassendi. 2? Alpetragius. 29. Catherina. 



30. Cyrillus. 31. Theophilus. 32. Vendelinus. 33. Langreen. 

 34. Uuttemberg. 35. Albategnius. 36. Alphonsus. 37. Ptolemy. 

 38. Binpland. 39. Reaumur. 40. Hipparchus, 41. Letronne. 

 42. Grimaldi. 43. Flamsteed. 44. Encke. 45. Biccloli. 

 46. Copernicus. 47. Stadius. 48. Pallas. 49. Pliny. 50. 

 Henelaus. 51. Aristarchus. 52. Cleomedes. 53. Linnaeus. 

 54. Autolycus. 55. Arlstillus. 56. Archimedes. 57. Cassinl. 

 58. Struve. 59. Eudoxus. 60. Aristotle. 61. Plato. 62 

 Gartner. 63. Endyrolon. 64. Atlas. 65. Hercules. 



MOON : APPEARANCE OF THE EARTH'S SATELLITE TO A TERRESTRIAL OBSERVER 



Based on .\aitnyth and Carpenter'! Picture Map. By courteiy of John Murray 



cleft with a hatchet. There are 

 numerous smaller clefts on the 

 moon, known as rills. Near the 

 crater Thebit is The Straight Wall, 

 with one side 1,000 ft. higher than 

 the other. 



The lunar seas were evidently 

 once covered with liquid. Fracas- 

 torius, on the border of the sea of 

 Nectar, was once a complete ring, 

 but the wall towards the sea has 

 been destroyed, leaving, however, 

 a mark to show where it stood. 

 Numerous marks of other ruined 

 formations are discernible on the 

 seas. The destroying agency is 

 thought to have been very liquid 



lava, either ejected in sudden 

 streams from the interior, or 

 produced by the impact of some 

 large body from outside. 



While there is no present 

 volcanic activity on the moon, 

 there is an agency which may 

 produce some changes in it ; this 

 is the great difference of tempera- 

 ture between day and night. The 

 rocks in the sunshine probably 

 reach the temperature of boiling 

 water, while at night they reach 

 the cold of space, several hundred 

 degrees below zero. The alternate 

 expansion and contraction may 

 cause the occasional collapse of 



steep walls. Thus the crater Liiu 

 naeus, formerly described as very 

 deep, is now a shallow, whitish 

 depression. 



The complex problem of the 

 motion of the moon arises from the 

 action of the sun, whose attraction 

 on the earth and moon is appre- 

 ciably different. The eccentricity 

 of the orbit, the direction of its 

 major axis, the orbit-plane, are all 

 continually changing. The earth's 

 equatorial protuberance and the 

 planetary attractions also produce 

 appreciable disturbances. Dr. 

 Ernest Brown, after 25 years' 

 work, has completed new lunar 



