44 KANSAS CITY REVIEW OF SCIENCE. 



This being the case it necessarily follows that if '* Low " is on a high line of lati- 

 tude, say 45° to 50° N., we will have south winds, which are warm. If 

 " Low" is on a low line, say in the Cotton States, to the north thereof we will 

 have cold north winds. " High " representing the atmospheric hill, there is no 

 movement of air towards it ; so no warm air, or more than relatively warm, can 

 be present in the area of " High" and the atmosphere there must necessarily be 

 relatively cool. 



It will be seen that what warm "the wind," and the movement of " Low," 

 which produces the winds, are quite different forces; yet it is often asked if the 

 speed of " Low " is caused by the power of wind. The wind is dependent upon 

 " Low " and not " Low " upon the wind. 



Although " High" follows and surrounds " Low " it does not do so in any 

 regular manner. Nature in this department is very irregular, and the Weather- 

 Map which is, as it were, a photograph of these changes of the atmosphere from 

 hour to hour, plainly reveals this, and shows that "High" follows and moves 

 with "Low" over the country; entering generally at the west, locally from the 

 south to the extreme northwest, and that the two pass over the country in all 

 conceivable shapes and on all sorts of lines. 



We may imagine the whole of the atmosphere as a great sea of " High" 

 with the valley " Low " moving through it. Sometimes alternate areas of " Low " 

 and " High " pass from the west towards the east; sometimes the " High" will 

 be in the north, the ' ' Low " in the south ; the ' ' High " in the south and ' ' Low " 

 in the north, or additional variety be given by combinations of these factors. 

 Then this variety is still increased by their size, shape and speed as they pass 

 across the country. 



When we have made ourselves familiar with these forces and their move- 

 ments we will be prepared to understand the peculiar features of the weather — 

 why it is hot at the north while cool at the south — why one season is cool, wet 

 or dry, another hot and dry, or even wet; no matter what the weather may be, 

 the Map satisfactorily explains it all. 



" J-1 igh " and " Low " travel in irregular belts. At times we will have 

 "Low" in the north; "High" central, and another belt of "Low" to the 

 south. This neutralizes the effects of heat and cold. Take away the north 

 " Low " and it will be very cold in the south, and in winter, the Gulf States be 

 apt to have a snow-storm ; take away the south " Low " and it will be very warm 

 throughout the country. During the winter and spring we generally have more 

 south "Lows," and "Lows" which travel from the southwest to the northeast, 

 than in the summer. But there is no regularity about it. A so-called " north- 

 east storm" is the result of a southwest "Low," or an area of low barometer 

 advancing from the southwest. 



When a storm-centre is to the west of a locaUty that locaUty will have an 

 easterly wind, and when the centre has passed to the east a westerly wind will 

 follow in its track, west, southwest, or northwest, depending on the line on 

 which the "Low" is travelling. 



