In a book published in 1905 entitled _The Rational Almanac_, by Moses B. Cotsworth, of York, the author states that (p. 397), "The explanation is apparent from the Great Pyramid's Slope, which conclusively proves that when it was built the latitude of that region was 7°·1 more than at present. Egyptian Memphis now near Cairo was then in latitude 37°·1, where Asia Minor now ranges, whilst Syria would then be where the Caucasus regions now experience those rigorous winters formerly experienced in Syria." But the reality of this comparatively great change of latitude in the position of the Great Pyramid can be easily disproved. Pytheas of Marseilles--who lived in the time of Alexander the Great, about 330 B.C.--measured the latitude of Marseilles by means of a gnomon, and found it to be about 42° 56'½. As the present latitude of Marseilles is 43° 17' 50", no great change in the latitude could have taken place in over 2000 years.[78] From this we may conclude that the latitude of the Great Pyramid has _not_ changed by 7°·1 since its construction. There is, it is true, a slow diminution going on in the obliquity of the ecliptic (or inclination of the earth's axis), but modern observations show that this would not amount to as much as one degree in 6000 years. Eudemus of Rhodes--a disciple of Aristotle (who died in 322 B.C.)--found the obliquity of the ecliptic to be 24°, which differs but little from its present value, 23° 27'. Al-Sufi in the tenth century measured the latitude of Schiraz in Persia, and found it 29° 36'. Its present latitude is 29° 36' 30",[79] so that evidently there has been no change in the latitude in 900 years. CHAPTER V The Moon The total area of the moon's surface is about equal to that of North and South America. The actual surface visible at any one time is about equal to North America. The famous lunar observer, Schröter, thought that the moon had an atmosphere, but estimated its height at only a little over a mile. Its density he supposed to be less than that of the vacuum in an air-pump. Recent investigations, however, seem to show that owing to its small mass and attractive force the moon could not retain an atmosphere like that of the earth. Prof. N. S. Shaler, of Harvard (U.S.A.), finds from a study of the moon (from a geological point of view) with the 15-inch refractor of the Harvard Observatory, that our satellite has no atmosphere nor any form of organic life, and he believes that its surface "was brought to its present condition before the earth had even a solid crust."[80]