ON THE METEOROLOGY OF PORT LOUIS. 



135 



Table XVIII. — Showing the Mean Humidity of the Air for each Month and 

 Year, from 1860 to 1866, both inclusive. 



"We have seen that Table XIII. indicates a decrease of vapour-pressure. 

 We now see that Table XYIII. iudicatcs a decrease] of humidity ; in other 

 words, an increasing dryness of the air. This decrease is perhaps more ap- 

 parent when we take the means for periods of two years each. Thus : — 



Years. 

 i860 

 1861 

 1862 

 1863 

 1864. 

 1865 



Humidity. 



•• 73'6]. 



•• 717/ 

 .. 7i-2| 



.. 71-1 J 



71-2 



Means. 

 72"6 



7I-I 



7i"o. 



The humidity for 1866 is so small as to render it almost certain that the 

 mean for 1866 and 1867 wiU be the least of aU. 



These results are interesting in connexion with the destruction of the fo- 

 rests, and the diminishing sugar-crops. 



The year 1866 was remarkable not only for diminished humidity, but also 

 for diminished vapour-pressure, diminished rainfall, absence of hurricanes, 

 and a severe drought, which, after destroying a large portion of the young 

 canes, was followed by a terrible fever, which has not yet disappeared. At 

 the Observatory the 



Humidity was 66-4 (100—0). 



Vapour-pressure 0-619 inch. 



EainfaU 20-56 inches. 



