330 



NOTES ON THE RAINFALL. 



26th, a thunderstorm brought the drought to a temporary end 

 with a rainfall of over half-an-inch at all the stations. It 

 proved a very acceptable rainfall, coming as it did after more 

 than three weeks of hot, rainless weather. Writing about it 

 Mr. Picot said : " Heavy thunderstorm at 2 a.m. ; a boon to 

 everybody." Another electrical disturbance, but with much 

 smaller rainfall, passed across the islands on Saturday after- 

 noon, the 29th, the peculiarity in connection with which was 

 the occurrence of a violent whirlwind and dust-storm which 

 immediately preceded the dash of rain. The enormous quan- 

 tity of dust whirled up by the wind was a striking feature of 

 the phenomenon, and to those exposed to the brunt of the 

 squall the dust was suffocating in its violence. The storm, 

 which was of the line-squall type, was afterwards traced right 

 across the British Isles. From the recorded observations it is 

 shown to have " first struck the extreme end of Cornwall 

 about 2 p.m. on July 29th, and passed across Shetland at 

 3 p.m. the next day." At Guernsey the whirlwind and dust- 

 storm occurred at 3 p.m. 



" Absolute " droughts followed each other in quick 

 succession during the summer months, especially by the way 

 at Sark where a total for the year of five occurred, against 

 four at Alderney and two at Guernsey. In the tabulation of 

 droughts at the end of this paper it will be seen that Guernsey 

 (Les Blanches) and Sark recorded one each in August. 

 Alderney escaped the distinction ( !) because of a fall of 

 0*04 in. of rain on the 12th. On the other hand both Sark 

 and Alderney ended a three weeks' drought on September 

 18th in which Guernsey was barred from participating just 

 because a shower, again giving a paltry 0*04 in. of water, fell 

 on the 4th. 



However all droughts, and at the same time the won- 

 derful summer of 1911, with its ideal hot and sunny days, 

 came to an abrupt and permanent end on September 18th, for 

 rain set in everywhere the next day and a spell of unsettled 

 cyclonic weather began, destined to last with but little break 

 to the end of the year, and beyond it. 



October proved an interesting period because of several 

 peculiarities in the distribution of the rainfall. To begin with, 

 while 0*72 in. was recorded by Capt. Henry, at Sark, on the 

 5th, only 0*49 in. fell at Guernsey (Les Blanches), while 

 Alderney had nothing more than 0*17 in. This occurred with 

 a strong E. wind and a thundery type of weather, for thunder 

 rolled at Guernsey for some time during the early afternoon. 

 Two days later, on Saturday morning, the 7th, when two 



