﻿TIN MINES. 



205 



Tin Mines. 



I GAVE you, on a preceding page, a sketch of diamond mines. 

 I now have a word or two to say about tin. Tin has been found in 

 several countries, but very few mines have proved of any great 

 value. The tin mines of Cornwall, England, are the best. It is 

 supposed that these mines have been worked over two thousand 

 years. There are between twenty and thirty now in use. The 

 descent to them is by a perpendicular pit called a shaft. A rope 

 with a bucket, or kibbut, at each end, is fixed to a windlass at the top, 

 and a load carried up and another one oown at the same time. The 

 descent in one of these buckets is rather hazardous, though acci- 

 dents rarely occur. 



When the vein of ore is first discovered, it is frequently less than 

 an inch thick ; but as the miners follow it, it increases, and becomes 

 more valuable. The adjoining rock is blasted with gunpowder, to 

 get at the ore conveniently. Frequently the vein ceases abruptly, 

 as if it had been suddenly snapped off. When such is the case, 

 experienced miners soon discover the disconnected part, and proceed 

 again in their excavations. The tin mines now worked at Polgooth, 

 in Cornwall, are nearly seven hundred feet in depth. The water 

 which accumulates at the bottom of the mines is generally pumped 

 out by steam-engines of great power. Sometimes, when the mine 



