3 1 6 Dove on the Law of Storms. 



winds, and of the monsoons, the numerous examples of greatly 

 diminished pressure ushering in the typhoons and West India 

 hurricanes are well known. 



[M. Dove then proceeds to recount several such instances. In 

 1837 the harbor master at Porto Rico warned the shipping in 

 the port to prepare against a storm, as the barometer was falling 

 in an unusual manner ; at 8 p. m. the preceding evening it had 

 stood at 333 //7 .28, and had sunk to 315 /// .27. The precautions 

 taken were unavailing ; thirty-three vessels at anchor were all 

 destroyed, and at St. Bartholomew alone two hundred and fifty 

 buildings were overthrown. At the same time the barometer fell 

 at St. Thomas from 337 /// to 316"', and the ravages of the hur- 

 ricane were even greater than at Porto Rico. He describes the 

 violent effects of the wind on this and other occasions, in the de- 

 struction of vessels in the harbor, forts, houses, and larger build- 

 ings ; in dragging large guns (twenty-four pounders) along the 

 ground ; driving boards through trees and walls several inches in 

 thickness, &c. &c. He refers also to Gen. Baudrant's account 

 of the destruction of Basse Terre in Guadaloupe by a hurricane 

 in 1825 ; and to hurricanes in 1828 and 1836 in the island of 

 Mauritius, where in 1828 the barometer fell to 316'", and in 1836, 

 having stood at 337 /// .00 at 5 a. m. on the 6th, it had fallen to 

 317"'.85 at 8 a. m. on the 8th. M. Dove says further in a note, 

 " A striking instance of the great mechanical power, even of 

 smaller hurricanes, occurred near Calcutta in April, 1833, when 

 a revolving storm, not above half an English mile in breadth, pass- 

 ed between Calcutta and the great salt-water lake three miles to 

 the east of that city, and in the space of four hours, on a track 

 of sixteen miles in length, caused the death of two hundred and 

 fifteen human beings, and injured two hundred and twenty-three. 

 It overthrew one thousand two hundred and thirty-nine fisher- 

 men's huts ; a bamboo was driven quite through a wall of five 

 feet thick, piercing the covering of masonry on both sides, so 

 that the Editor of the Indian Review says a six-pounder would 

 scarcely have had the same effect."] 



If two phenomena frequently occur together, we may surmise, 

 with some degree of probability, that they have a casual connex- 

 ion ; but it may remain quite undecided which is the conditional, 

 and which the contingent phenomenon ; or both may be effects 

 of a third phenomenon, which is itself their common cause. 



