SOUTHERLY BURSTERS. 



39 



for an hour at the electrometer at the ends of the exploring wire. 

 The approach of the true burster is indicated by a peculiar roll of 

 clouds, which when once seen cannot be mistaken ; it is just above 

 the south horizon, and extends on either side of it 15 or 20, and 

 looks as if a thin sheet of cloud were being rolled up like a scroll 

 by the advancing wind. 



" Clouds of dust, which penetrate everywhere, announce the arrival 

 of the wind, scud flies by overhead with great rapidity, being 

 sometimes less than two thousand feet high ; rain may follow, but 

 if so, thunder and lightning come first. The velocity of wind is, 

 in most cases, greatest within the first two hours, and varies from 

 thirty to seventy miles per hour, but is usually from fifty to sixty 

 and the rate of progress along the coast about forty miles per hour. 

 The change of wind is sometimes very sudden ; it may be fresh 

 north-east, and in ten minutes a gale from south, hence vessels 

 not on the lookout are sometimes caught unprepared, and suffer 

 accordingly. When the wind is light these storms are often 

 carried to sea by the general easterly motion of the atmosphere, 

 and may be seen passing by, the peculiar clouds indicating unmis- 

 takably their position." 



APPARENT DOUBLE BURSTERS. 



The following is a detailed account of a double burster, or of 

 two distinct simultaneous bursts on different parts of the coast. 

 It will be convenient to commence with a table, showing the 

 hours at which the burst reached various points on the coast-line, 

 with relative rates of travel from place to place : 

 10th October, 1893. 



