CLIMATOLOGY OF RAIN-FOREST REGION. 



17 



During these months the number of totally clear days was 6, the 

 number of totally cloudy or rainy days was 50, the number of partially 

 cloudy days 95. The total rainfall for these five months was 37.07 

 inches as contrasted with the mean of 41.27, while the number of rainy 

 days was 74, the mean number being 72.7. This is partial, if not 

 absolutely conclusive evidence that the above percentages are not 

 below the normal. 



The typical course of the day's weather is: clear from sunrise until 

 9 to 11 a. m., intermittently or entirely cloudy until nearly sunset, 

 with two to three hours of fog in the mid-day or early afternoon, the 

 sun setting clear. Rain usually occurs in the mid-day or early after- 

 noon and the night is clear. During the summer months the percent- 

 age of sunshine is much greater than in the months tabulated above, 

 but is so intermittent that it would be impossible to determine its 

 percentage of the total number of hours without the use of appropriate 

 instruments. 



WIND. 



The wind at Cinchona is prevailingly from the east and northeast 

 and commonly reaches its highest force at night and in the winter 

 season. Its influence on the vegetation is greatest on the peaks and 

 ridges, and the fact that the lowest humidities accompany high wind 

 may make its desiccating influence considerable. The monthly mean 

 velocities of the wind in miles per day at Cinchona for eight years (1892 

 to 1899 inclusive), as measured by a Negretti and Zambra anemom- 

 eter, are shown in table 9. The annual curve shows little save the 

 lower rate in the rainy months (flg. 1). 



Table 9. — Monthly mean wind velocity. 



The annual mean daily velocity: 32.8 miles per day. 



