362 CLIMATE. 



locality lying in the same latitude. The effects of this combination 

 of heat and moisture are to be seen in the rankness of the vegetation, 

 and in the rapid rusting of steel. Although the foregoing remarks 

 may be taken as generally applicable to the group, it should be 

 stated that on the lee side of a mountainous island, such as the 

 western end of Guadalcanar, there is a comparatively dry atmosphere, 

 and the difference is also shown in the character of the vegetation. 



The moderate intensity of the sun's rays in these islands is to be 

 ascribed to the presence of aqueous vapour in quantity in the 

 atmosphere. When, however, a thunderstorm and its accompanying 

 rain-squall are portending, the air is unusually dry, and the sun's 

 rays are very fierce. At such times it often ha])pens that the sky 

 is overcast ; and thus it comes about that the unwary traveller, by 

 rashl}'- baring his legs and arms, suffers severe sun-burns when he 

 least expects it. Waterton and other travellers have, thi-ough 

 ignorance of this fact, been laid up for several days, and even weeks. 

 I was unable to walk any distance for about ten days, after experi- 

 encing a severe sun-burn of the legs as the result of baring them 

 during an overcast day. The affection is peculiarly painful, though 

 it often excites but little sympathy. 



My remarks on the meteorology of this group will not be 

 complete without a short reference to the prevailing winds. The 

 South-east Trade Wind and the North-west Monsoon carry on a 

 continual struggle for the mastery in these islands. However, for 

 two-thirds of the year the Trade prevails, viz., from April to 

 November. The appended record of winds, which extends over a 

 considerable period, I have prepared from the observations made on 

 board H.M.S. " Lark " in different parts of the group, and from the 

 registers kept by Mr. Sproul and Mr. Howard at Santa Anna 

 and Ugi. It will be there seen that at the eastern extremity of 

 tliese islands, viz., in the vicinity of St. Christoval, the Trade 

 announces its onset in April by unsettled weather, and frequent 

 thunderstorms. In May, it becomes established, but, as Lieutenant 

 Leeper remarks, it blows in fits and starts, is interrupted by calms, 

 variable winds, and heavy rain-squalls, and does not blow home as 

 in Fiji and the groups to the eastward. At tbe opposite end of the 

 group, in Bougainville Straits, the Trade appears a month later, and 

 does not become established until June. In this locality, however, 

 it is more fitful than in, the eastern islands, blows lighter, and is less 

 to be depended on by the navigator. 



