1921] Brooks : Mountain Climates. 243 



range of 14" F., from 66° F. in the day to 52° F. in the 

 night ; at the other, at Tosari on a mountain blope, at a 

 height of 5,800 ft., the daily range is not more th.-n 7° F. 



At Tosari in Java the lowest temperature occurs just 

 before sunrise, as near the sea coast, but the temperatures 

 during the day at a height of about 5,800 ft. are very 

 different. In the morning clouds form with their upper 

 surface below the level of the station, and temperature 

 rises rapidly, the station receiving not only tliC direct and 

 very powerful radiation from the sun, but also that reflected 

 from the clouds. But during the day, as the heat of the 

 plains becomes greater, the level of the clouds rises, and 

 shortly after ten o'clock they reach the station, which then 

 becomes plunged in mist. Temperature now faUs rapidly, 

 but with great fluctuations of as nuich as 5° F. in a few 

 minutes as the clouds come and go. Consequently the 

 greatest heat of the day comes about ten o'ckck in the 

 morning, instead of in the afternoon as at lower levels. The 

 afternoons are cloudier and cooler. 



As a rule, at night the clouds either dispcse or sink 

 to a lower level, so that the nights are clear and dry, but 

 occasionally they will be cloudy and these nights will be 

 relatively hot and oppressively moist, the blanket of cloud 

 preventing the ground from radiating its heat. 



3, Humidity, Sunshine and Cloudiness. 



The chief characteristic of the humidity of tiie air at a 

 tropical mountain station is the rapidity with which it 

 varies. Above the clouds the air is very dry, but among 

 them it is satiuated with moisture. In the intense solar 

 radiation of the morning the air is as dry as thai of a desert 

 at noon ; a cloud drifts up, and even though no rain falls, 

 everything drips with moisture. The actual average 

 depends upon local conditions, but will probably be not 

 far from eighty per cent, of saturation during the days — a 

 figure indicating a quite considerable degree of moisture, 

 and much less during the nights, which would thus appear 

 cooler than they actually are relatively to the plains. 



The amount of bright sunshine will probably be very 

 considerable. At low level stations the sky is on the average 

 half covered with clouds, which means that on the average 

 sunny and dull days will occur with equal frequency, but 

 at a level of 5,000 ft. much of the cloud development will 

 take place below the station, which will thuG receive a 

 greater amount of sunshine, especially in the mornings. 

 Moreover, owing to the greater clearness of the air, this 

 sunshine will be far more powerful than on the plains. 

 Excess of sunshine and light is frequently dangerous to 

 Europeans in the tropics. 



4. Winds : The Alternation of Monsoons. 



But if there are not four seasons in the English sense, 

 there is a very definite division of the year into two seasons 



