LECTURES. 6 1 



has 70 per cent., Cornwall, Wales, West of Scotland and Norfolk 

 shew 60 per cent., and Stornoway and Dunrossness 80 per cent. 

 In February the figures are much the same, but less in the extreme 

 North. In March hardly any station in England shews above 50. 

 In April the only place reaching 60 is Valencia. Now in May, the 

 real dry weather values begin to appear in Hampshire. At 

 Southampton and Hurst Castle June is the driest month in the 

 whole year, while July is the wettest Summer month bringing the 

 well-known Lammas floods. August is as wet as July, but September 

 is much drier. October is wet again, and in November and 

 December we find the maximum, which in July and August was in 

 West Ireland, has moved up to Stornoway and Dunrossness. 

 Accordingly June and September are the two months with the 

 greatest prospect of dry days. The characteristic of our climate is 

 the frequency of the falls of rain. The individual falls are not often 

 excessive. Of course we thereby escape the extraordinary deluges 

 with which other countries are visited, and have nothing to compare 

 with the tremendous falls on the Hills in India and in Burmah. 

 I may mention that during the recent hurricane in the West Indies 

 the violent rainfall did far more damage than the wind, and amounts 

 varying from 10 to 20 inches fell continuously in 48 hours. 



The temperature is, of course, an item in the meteorologist's list of 

 things to be observed, to which much importance is attached from its 

 effect on animal and vegetable life, and probably that which is most 

 beneficial to the one equally suits the other, and that would be a 

 gradual rise in temperature from the end of January to the end of 

 July, and then a steady decline. If that were the case there would 

 be practically little or no need to take observations of the temper- 

 ature. But it is very far from being the case, and it becomes the 

 duty of the observer to record all the variations of the tempera- 

 ture and then seek to find out, if possible, the causes of the changes. 

 To do the first he is provided with self-recording thermometers to 

 give the maximum and minimum temperatures carefully verified at 

 Kew Observatory, which are placed in a screen 4 feet high, consisting 

 of a box of double louvred sides through which air passes freely, but 

 no direct sunlight or radiating rays, so that in this way the true shade 

 temperature can be obtained. The screen should also contain wet 

 and dry bulb thermometers from which can be deduced the tempera- 

 ture of the Dew Point, the Elastic Force of Aqueous Vapour and 

 the relative Humidity or percentage of saturation of the air with 

 aqueous vapour. 



