352 



PHYSIOGRAPHY. 



[chap. 



from pole to pole. Every place on the earth's surface will 

 therefore be just as long in sunshine as in shade ; and there 

 will be equal day and night throughout the world. 



Fig. 113. —The Eanh at the summer solstice. 



In passing from No. 2 to No. 3 in Fig. 112, the nights in 

 northern latitudes get longer, and the days shorter. When 

 the earth is in the position of No. 3, which is about December 



line drawn from the earth to the sun is supposed to lie in the plane 

 of the paper. A plane drawn ihrough both poles coincides with the 

 plane of the paper in Fig. 113 ; while, as the earth has moved through 

 a quarter of a circle in order to get into the position represented in 

 Fig. 114, the plane of the poles is now at right angles to that of the 

 paper ; and the north circumpolar region is seen, foreshortened, in the 

 upper part of the figure. 



