100. 



Ftpt a n ations -The letters A K, D, etc., refer to the details of the large engravkig which commences 

 each^Tsup ^^^^.WnniiwithlOO.refer to the 



asatoA 7e- the figure? 1 to 20 refer to certain minute details necessary to the illustration ot ™ e ™** a '«™ 

 £rt Thus the num 6er 100 (on this page) refers to the large illustration of the earth, clouds and moon as a 

 ^leXuuTl S.C.D. poin/to certain The*** 103 referto the 



sea ; hut the figures c *nd 4 refer, specifically, the first to sea, the second to land. A do *6 ™£ 

 6-104-means the derail 6 in <ZZ«fratfo» 104. By this simnle method, many thousands of instructive reter 

 ences will he made in the volume. The Index to 

 all technical and scientific terms unexplained in the text, 



the volume will he also a Glossary, and will explain 



The Eaeth, a, is 

 known number of 

 planetary bodies, 

 1. The form of 

 the earth is glJbu- 

 lar, but not quite 

 round, being fat- 

 tened at the poles, 

 d d. The 

 wttfter of the earth, 



one of an un- 

 i 



101. 



measured at its middle, or the 

 equator, is 7,926 (nearly 8,000) 

 miles ; its circumference about 

 24,900 (nearly 25,000) miles ; its 

 surface is estimated to amount to 

 198,943,750 (nearly 200,000,000) 

 square miles. It is surrounded 

 by a transparent gaseous body, 

 called, when spoken of in a com- 

 prehensive sense, the atmosphere ; 



