46 Charles Darwin. 



Darwin found that the internal surface was smooth 

 and completely vitrified. The walls of the tube 

 were about the twentieth of an inch in thickness. 

 The most remarkable feature about this was the 

 number of tubes in so restricted an area. The en- 

 tire region bore a bad name. In a single electrical 

 storm thirty-seven places were struck in the city of 

 Buenos Ayres and nineteen persons killed. 



In referring to this Darwin says : " I am inclined 

 to suspect that thunder-storms are very common 

 near the mouths of great rivers. Is it not possible 

 that the mixture of large bodies of fresh and salt 

 water may disturb the electrical equilibrium ? Even 

 during our occasional visits to this part of South 

 America, we heard of a ship, two churches, and a 

 house having been struck. Both the church and the 

 house I saw shortly afterwards : the house belonged 

 to Mr. Hood, the consul-general at Monte Video. 

 Some of the effects were curious: the paper, for 

 nearly a foot on each side of the line where the bell- 

 wires had run, was blackened. The metal had been 

 fused, and although the room was about fifteen feet 

 high, the globules, dropping on the chairs and furni- 

 ture, had drilled in them a chain of minute holes. 

 A part of the wall was shattered as if by gunpowder, 

 and the fragments had been blown off with force suf- 

 ficient to dent the wall on the opposite side of the 

 room. The frame of a looking-glass was blackened, 

 and the gilding must have been volatilised, for a 

 smelling-bottle, which stood on the chimney-piece, 

 was coated with bright metallic particles, which ad- 

 hered as firmly as if they had been enamelled." 



