116 



CLIMATIC CONDITIONS 



Difference. 



12 

 11 

 9 

 6 

 5 

 6 

 3 

 3 



17 

 15 



Difference. 



40 



45 



33 



25 



62 



RELATIVE HUMIDITY. 



The amount of moisture in the atmosphere is a factor of the highest 

 importance, especially in its influence upon personal comfort. The Nassau 

 observations show the presence throughout the year of a high humidity. The 

 official records give the average monthly values for the hours of 9 a. m. and 

 3 p. m. .The daily means determined from observations at these hours give 

 a value about 6 per cent too low, as the hours between sunset and sunrise, 

 when the percentages are highest, are not represented. 



A continuous record of variation in humidity throughout the day was 

 obtained during our stay in the Islands from June 25 to July 20, by means of 

 a Eichard hygrograph. This record made it possible to apply a correction to 

 the mean for the 9 a. m. and 3 p. m. observations in order to arrive at the 

 true daily mean humidity based on 24 hourly observations. The corrected 

 monthly values are shown in the column marked " mean " in the table below. 

 The humidity during the night hours ranges between 85 per cent and 90 per 

 cent, and during midda}^ is about 73 per cent. The amount of moisture in the 

 atmosphere is remarkably uniform throughout the year, while the daily range 

 is small, not varying much from 15 per cent. Such humidities as these com- 

 bined with the high temperature of the Islands would be very oppressive were 

 it not for the almost constant presence of a breeze. The presence of so much 

 moisture in the atmosphere is undoubtedly instrumental in diminishing the 

 power of the direct rays of the sun. 



