228 THE WEATHER. 



the east its vapors lie in contact with the earth and 

 ocean, and the electricity passes off silently as fast as it 

 accumulates. In a long continued storm the clouds 

 cover the whole heavens, and extend over a region of 

 many miles ; and they form so slowly that there is oppor- 

 tunity for a gradual escape of the fluid. But when, in 

 a sultry summer afternoon, black masses of cloud rise in 

 the west, forming very rapidly, and with rounded and 

 well denned boundaries, the fluid then accumulates 

 faster than it can escape, and after a time it darts to the 

 earth, or from cloud to cloud, producing the terrific 

 effects which we so often see. Splendid and appalling 

 as these results sometimes are, they are imitated precisely, 

 but harmlessly, by the apparatus of the lecturer. The 

 fluid is the same in its movements and in its character, 

 whether it sparkles on the table or thunders in the skies. 



When it darts to the earth, its aim is to pass Uirough 

 the best conductors it can find on its way. Hence it 

 strikes a tree ; that is, it chooses to come down through 

 the juices of the trunk ; for it will be recollected that 

 water was said to be a conductor. It often seeks a way 

 through the walls and partitions of a house, because it 

 finds there metallic or watery substances which help it 

 forward. But it must be remembered that it strikes these 

 subjects only so far as they furnish it a passage way to 

 the place for which it is destined. The common idea 

 that a penknife, or other metallic body, attracts the light- 

 ning is erroneous. A lightning rod suspended horizon- 

 tally in the air would not attract lightning. It is only 

 when it forms a connexion between the place where the 

 electricity is, and that towards which it tends to move. 



The following remarkable case will illustrate the prin- 

 ciple. The truth of the statements may be relied on. 

 We extract it from the Lon. Phil. Trans. 



Remarkable Case of a House Struck by Lightning. 



1 Thomas Olivey, a respectable farmer, had returned 

 from the field, about a quarter before twelve o'clock, and 

 had all his family round him in the kitchen, except his 

 daughter, who was in the hall. There was a pan over 

 the fire in the kitchen chimney, full of boiling water. 

 The farmer was sitting by the fire, and his wife on a 



