METEOROLOGICAL FACTORS AND PHENOMENA. 423 



•of decades or cycles, or the changes which are the result of vast periods of time 

 — producing these, at present, gradual climatic changes which cause the surface 

 of the earth near the poles to be more directly exposed to the rays of the Sun. 



These last three factors are the general results of the three motions of the 

 Earth in connection with the heat of the Sun. The third motion of the Earth, 

 however, seems to be very little regarded, yet it is as important as the other two 

 which cause the daily and yearly changes of the seasons. The three motions of 

 the earth are best represented by the spinning top, including the state known as 

 "dying out." It has one (first) motion on its axis; one (the second), along the 

 ground; another (the third) back and forth, which in combination with its rotary 

 motion causes the upper part, which would correspond to the polar axis of the 

 Earth, to describe a circle in the space above it. This third motion of the Earth 

 at present is very gradual, yet there may have been a time when the change was 

 very sudden, and nothing it would seem would so well account for these pecu- 

 liar and rapid chmatic changes of past periods of the Earth's history, when the 

 features of the present torrid zone prevailed as far north as Siberia, and were 

 changed so rapidly as to entomb alive the huge mammoth, nothing it would 

 seem would so well account for this phenomenon as a sudden change in the in- 

 clination of the Earth's axis. 



The next great factor in our meteorological economy is the concentration of 

 the Sun's rays along certain paths of the Earth's surface. These concentrations 

 are always on general lines from the west toward the east and are termed areas of 

 low barometer — /. ^., the heat of the Sun concentrating on certain points pro- 

 duces there a rarification of the air, or would-be vacuum which is the agent to 

 establish a current of air toward this point. The water present on the Earth is a 

 latent factor in the case; it not only provides moisture to immediate surroundings 

 but furnishes the material for clouds which are simply suspended moisture and 

 which are ever ready, when formed, for transportation to wherever the prevail- 

 ing winds may dictate. The concentration of the Sun's rays producing the area 

 of low-barometer, technically termed "low," is the agent or power that creates 

 the winds. 



All these factors, winds, clouds, motion, conditions for existence, all come 

 through that great agent of heat, the Sun. The minor factors though great in 

 themselves, all depend upon are subordinate to the Sun ; and it is only when we 

 come to understand the importance of these minor factors that we can by compar- 

 ison begin to comprehend the greatness of the major factor and the infinite wis- 

 dom that estabhshed all the beautiful mechanism of our terrestial system. 



On the surface of the Earth we have the factors high and low thermometer 



and high and low barometer. The thermometer we know is the register of the 



eat, and other things being equal, it will be hottest where the Earth receives 



e most direct influence from the Sun. The belt comprising the torrid zones is 



Wmer than the temperate, and the temperate warmer than the frigid, and it 



uld seem that there would be no exceptions — it would seem at least in the im- 



'^'ate vicinity of the Equator it should be warmer than half way from there to 



