200 KANSAS CITY REVIEW OF SCIENCE. 



towards the east they do not do so on any regular line or course. They enter 

 the territory of the United States at various points. On the Pacific their most 

 objective points are above and below Cape Mendocino, the extreme western 

 point of our western border. 



This, however, is a mere general statement, for they never enter twice alike 

 and vary with the season and seasons. As a rule they enter and cross the country 

 on a higher line of latitude during the warmer than during the colder months. 

 Others enter at the southwest, or through Mexico and Texas ; while still others 

 enter from the region of the West Indies, sometimes striking quite far inland; at 

 other times merely skirting the coast. These latter ones, from want of stations in 

 the West Indies we have very httle forewarning of. Although ' ' Low " travels from 

 the west towards the east, it often in its passage, travels on lines almost due north 

 and south for twelve or fifteen hundred miles, and perhaps more. For want of 

 the proper stations we cannot trace its full course. So these " Lows" that come 

 up from the south are undoubtedly ones that are travelling on some erratic course. 

 These areas of high and low-barometer, "High" and "Low," in addition to 

 travelling as above stated, also travel in belts around the world, and all the while 

 vary as to the territory they cover. At times "Low" will be in the north, 

 "High" central, and another "Low" in the south; or we may have "Low" 

 central, with " High " each side. It is always changing, and these changes pro- 

 duce the changes of the weather from hot to cold, wet to dry ; and all the changes 

 are the result of the relation which these two powers "High" and " Low" bear 

 to each other. 



The wind being towards " Low," it follows if " Low" is in the north we will 

 have south winds, if in the south, north winds, and these winds partake of the 

 qualities of the locality from which they come. There are times, however, when 

 the north winds will not be very cold nor the south winds very warm, and this 

 will be when these respective winds come from an area of high-barometer that is 

 not very far away. If " High " lies immediately to the north, the north winds 

 cannot be from a great distance north, and if " High is immediately to the south 

 the south winds will not be from far south, therefore will have little opportunity 

 to become heated. " High" is like a great mountain ridge; it is the mountain 

 ridge of the atmosphere. The wind is from the centre of the ridge or highest 

 point of " High; " from the centre outwards, so on the north side of " High" 

 the wind will be towards a north " Low," while on the south side it will be to- 

 wards a south "Low," etc. 



The lines -which these areas of " Low " make across the country are infinite, 

 never twice alike ; and although their general course is from the west towards the 

 the east, or towards the rising sun, they at times travel due west, but it is always 

 towards the latter part of the day or at night. So soon as the sun reappears in 

 the- east and establishes its centre of heat " Low" immediately advances towards 

 it. These areas of Low-barometer not only vary in direction, but in speed, ex- 

 tent and intensity, sometimes being very small, not more than a few hundred 

 miles in diameter, then extending over one-half of the United States and at times 



