ON THE STORM OF THE 18TH OF APRIL, 1850. 313 



colour, projected on a sky of a paler tint, while the rugged outliers 

 from the mass, of the peculiar form which indicates a high degree 

 of electrical tension, showed plainly that a storm was approaching. 

 About half-past three o'clock it burst forth. The flashes of light- 

 ning (generally forked) succeeded one another with rapidity, and 

 at length the roar of the thunder seemed continuous. Some persons 

 who observed the 'phenomena from a distance were able to dis- 

 tinguish the two strata of oppositely electrical clouds, and to see 

 the electrical discharges passing between them. 



Hitherto the wind was light, and there was that peculiar close- 

 ness in the air which is the result of high temperature and excessive 

 humidity. Shortly before four o'clock the rain commenced; this 

 was followed almost immediately by discharges of hail, and at 

 four, P. M., the terrific tornado, which was the grand and peculiar 

 feature of this storm, reached us. 



This gale, which appears to have been a true whirlwind, first 

 sprung up from the south-east, driving the hail before it impetu- 

 ously. It then suddenly, and apparently in an instant, shifted to 

 the point of the compass diametrically opposite, and blew with 

 increased violence from the north-west. The noise about this time 

 of the shifting of the wind was terrific, and arose (as is conjectured 

 respecting similar tropical phenomena) from the confused conflict 

 of hail in the air. The size of the hailstones, as well as the 

 vehemence of the gale, appeared to be greater during the second 

 phase of the storm than the first. These masses, many of which 

 were as large as a pigeon's egg, were formed of a nucleus of snow 

 or sleet, surrounded by transparent ice, and this again was suc- 

 ceeded by an opaque white layer, followed by a second coating of 

 ice. In some of them I counted five alternations. 



In less than ten minutes the tornado had passed. The wind 

 returned to a gentle breeze from the south-west, the clouds dis- 

 persed, and the weather became beautiful. All the phenomena, 

 the direction of the gale perpendicular to that in which the storm- 

 cloud was advancing, and the sudden reversal of that direction, 

 seem to prove that it was a tornado, whose centre passed directly 

 over the place of observation. It is evident, on comparing the 

 direction of the wind when the whirl first reached this part of the 

 town, with that of the progressive motion of the vortex itself, that 

 its rotatory motion was retrograde, or in an opposite direction to 

 that of the hands of a watch with its face upward. It is deserving 



