106 THE WORLD. 



plane of the ecliptic, -then, at all seasons of the year, the days and 



* 



nights would have been equal all over the world, for, as will be 

 seen on reference to the figure on page 105, the sun would shine 

 from pole to pole, and as it would illuminate but half the globe at 

 once, a spectator any where on its surface, would be just as long 

 in passing through the unilluminated as the illuminated portion. 





Thus, a spectator at A, on the parallel of latitude B C, would be 

 just as long in moving through the hajf of the unilluminated por- 

 tion of the earth B A, -as through half the illuminated A C. This 

 is the case at the equinoxes. When the sun is in either of those 

 points of his orbit which crosses the equator, then it illuminates 

 the globe from pole to pole, i. c. when he is in either of the points 

 0, or XII, see the figure on page 91. We have already shown 

 that the apparent diurnal path of the sun through the heavens due 

 to a rotation of the earth upon its axis, is in what is called a diurnal 



