OR, PLAItf TEACHING. 



49 



or promontory, 4 ; ex. lat. 35 3 S., 

 long. 28° E. A lake, 5 ; ex. lat. 



254. 



255. 



40° N., long. 50° E* A gulf, 6 ; 

 ex. lat. 35° N., long. 90° W. A 

 strait, 7 ; lat. 60^° N., long. 



170° W.f At 

 about 23^° from 

 the equator, on 

 each side of it, 

 there are dot- 

 j fed^ Z^es, which 

 do not belong 

 to the parallel^, 

 256< y>f latitude 0- 

 fer to a larger map). At ^about 

 60 1° from the equator tftere are 

 other dotted lines, which also are 

 distinct from the lines of latitude. 

 The spaces within these dotted 

 lines form the northern tropic, or 

 tropic of cancer, 10, and the south- 



257. 



em tropic, or tropic of Capricorn. 

 12. The word tropic signifies c 



* The Caspian Sea is strictly a lake. 



t We cannot state the latitudes and longitudes 

 precisely, on account of the emallness of the maps ; 

 but nearly enough for purposes oi example. 



return. On June 21, the sun is 

 directly over the northern tropic, 

 10 ; on December 21, it is directly 

 over the southern tropic, 12. The 

 change in the relative situations 

 of the sun and the earth is owing 

 to the annual revolution of the 

 earth around the sun. A line 

 runs across each hemisphere, 

 in the form of a curve, describ- 

 ing a path from the tropic of can- 

 cer to the tropic of Capricorn, 8. # 

 This is called the ecliptic ; it de- 

 scribes the path of the sun over 

 the earth, which is caused by the 

 deflection or variation of the earth 

 from a direct course around the 

 sun. The sun apparently passes 

 from the tropic of cancer to the 

 tropic of Capricorn. The effects 

 of this transit are — the changes 

 4$ seasons, periodical winds, 

 T storms, and rains, alteration of 

 the duration of darkness and 

 light, etc.f The same lines which 

 divide the arctic, 9, and antarctic 

 circles, 13, from the tropics, 10, 

 12, and the tropics from the equa- 

 torial, or central helt, 11, LI, of 

 the earth serve to mark the zones, 



258. 



14, which indicate the different 



•emperatures of those great divi- 



* Kefer to a larger map for the ecliptic. 



t An explanation of these changes will he reserved 

 for a future chapter. They will, moreover, be fre- 

 quently referred to and simplified in connection with 

 various subjects. 



