Ill ELECTRIC PHENOMENA 63 



latter case is remarkable, as the electric fluid must have turned 

 back at the acute angle of 26°, to the line of its main course. 

 Besides the four tubes which I found vertical, and traced be- 

 neath the surface, there v^ere several other groups of fragments, 

 the original sites of which without doubt were near. All 

 occurred in a level area of shifting sand, sixty yards by twenty, 

 situated among some high sand-hillocks, and at the distance of 

 about half a mile from a chain of hills four or five hundred feet 

 in height. The most remarkable circumstance, as it appears to 

 me, in this case as well as in that of Drigg, and in one described 

 by M. Ribbentrop in Germany, is the number of tubes found 

 within such limited spaces. At Drigg, within an area of fifteen 

 yards, three were observed, and the same number occurred in 

 Germany. In the case which I have described, certainly more 

 than four existed within the space of the sixty by twenty yards. 

 As it does not appear probable that the tubes are produced by 

 successive distinct shocks, we must believe that the lightning, 

 shortly before entering the ground, divides itself into separate 

 branches. 



The neighbourhood of the Rio Plata seems peculiarly sub- 

 ject to electric phenomena. In the year 1793,^ one of the 

 most destructive thunderstorms perhaps^^on record happened at 

 Buenos Ayres : thirty-seven places within the city were struck 

 by lightning, and nineteen people killed. From facts stated in 

 several books of travels, 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 sufficient to dent the wall on the 



1 Azara's Voyage^ vol. i. p. 36. 



