Ji;i,Y 18114.] BOTANICAL SOCIETY OF EDINBUKGH. 239 



other places in the same latitude. In general terms the 

 climate may be described as liot, damp, and rainy, with 

 a fair amount of bright sunshine, moderate winds, and 

 occasional hurricanes of terrific violence. The higher 

 parts of the island are much cooler, but very much 

 damper and more rainy than at the coast. From observa- 

 tions made at the Koyal Alfred Observatory, situated at 

 Pamplemousses, and 179 feet above sea-level, I am enabled 

 to give the following particulars of the climate of Mauritius 

 near the coast. Mean atmospheric pressure, reduced to sea- 

 level, 30"082 inches ; lowest, 27*95 inches in the great 

 hurricane of 29th April 1892, when the wind reached a 

 velocity of 121 miles per hour. The mean velocity of tlie 

 wind is only 11 "-l miles per hour, and storms and gales 

 very seldom occur. During the thirteen years 1876-88 

 the wind exceeded 40 miles per hour on three occasions 

 only. The mean temperature in the shade is 74°'8 F., 

 highest 96°'2 F., and lowest 48° F. The mean annual 

 rainfall is 47*02 inches, but the quantity varies con- 

 siderably in different years, and it has ranged from 29*74 

 inches to 71*86 inches. The average number of days of 

 rainfall is 200. The relative humidity of the atmosphere 

 is 73*7 per cent, of saturation, the highest recorded on any 

 one day was 97 per cent., and the lowest 38*4 per cent. 

 In 1888 the total duration of bright sunshine was 62 

 per cent, of the possible bright sunshine, or, in other 

 words, the sun was not obscured by clouds during 6 2 

 per cent, of the time it was above the horizon. 



Mauritius is almost encircled by a coral reef, which 

 in some places extends two or three miles out from the 

 .shore. From one to one and a half mile beyond the 

 outer margin of this reef the 100-fathom line of soundings 

 is reached, except at the north end of the island, where a 

 shallow sea extends 15 miles to the north. The sea over 

 the greater part of this northern bank is under 30 fathoms 

 deep, and on the bank there are numerous shoals and 

 reefs, besides a few small islands of volcanic formation. 

 The most distant of these islands are Ptound Island and 

 Serpent Island. The former is situated 13 miles- north- 

 east of the north end of Mauritius, and the latter lies 1 1 

 mile north of Eound Island. Beyond the 100-fathom 



