SOIL AND CLIMATE. 
179 
the hills will take us into a different climate from 
that of the plains. 
3. As we ascend the mountains we find that the 
air gets about one degree cooler for every 300 feet 
above the sea. Thus, at Kingston, which is not far 
above the level of the sea, the average warmth of 
the air is 79 degrees; while 5000 feet up on the 
mountains, in the Hill Garden of Jamaica, it is only 
63 degrees. 
4 . There is even a greater difference between the 
amount of rain at these two places — more than three 
times as much falling at Hill Garden as at Kingston. 
This is because the trade-winds, before reaching the 
city, are drained of much of their moisture by the 
mountains lying to the north and east. 
5 . These facts show that the climate is not the 
same in all parts, even in a small country like 
Jamaica. 
If we were quite free to choose where to live, no 
doubt we should make it our first care to choose a 
spot where the soil and climate were not likely to 
be harmful to our health. 
6. In the first place, the drier the soil the better 
it would be as a site for our dwelling. Sand, chalk, 
limestone, and gravel let the water pass freely 
through them ; but soils that are clayey hold it and 
become soaked. 
7 . By digging we may find water soaking the soil 
only two or three feet below the surface, or in other 
