G. GENERAL NATURAL HISTORY AND ZOOLOGY. 283 



lined to the hunt after these prehistoric excavations, which, 

 whenever cleared out and carefully examined, always revealed 

 the mineral in question. This result was so constantly met 

 with that Professor Kerr has been satisfied for some time 

 that in these mines we have the work of the contemporaries 

 of the mound-builders, and the localities whence they derived 

 the mica. What use they made of it we can not say ; but it 

 is suggested that it may have served the purpose of mirrors, 

 or possibly have been used as windows, as well as for orna- 

 ment. 



According to Professor Kerr, the number and size of these 

 mines is remarkable, some of the open cuts being more than 

 a hundred feet in diameter and twenty or thirty in depth, 

 even after the caving in and filling up of centuries of weath- 

 ering. The tunnels often extend inward several yards, but 

 are said to be too small for a man of ordinary size to work in. 

 These show distinct marks of the tool in the granitic wall, as 

 if made by a chisel-shaped instrument about an inch broad. 

 Numerous plates of mica are found in these tunnels and ex- 

 cavations, some of them trimmed to particular shapes ; but 

 nothing in the way of implements has been hitherto detected, 

 with the exception of one small piece of wood, about an inch 

 thick and two inches wide, and more than a foot in length, 

 having a slight depression near one end, as if for the carrying 

 of a light. 



These ancient works are known among the people as " sink 

 holes " and " caves," and in them are frequently found blocks 

 of mica weighing 500 to 1000 pounds, having plates three feet 

 in diameter. Many curious minerals are often found asso- 

 ciated with the mica in the feldspar matrix, the most abun- 

 dant and conspicuous being beryls, some of which have been 

 found weighing twenty pounds. 



These facts, as already stated, open up a new chapter in 

 the history of our aborigines, illustrating the character of the 

 commerce carried on at a very remote period, and showing 

 the magnitude of the operations, and the extended period of 

 time over which they must have been prosecuted, to enable 

 a people furnished with nothing better than wooden and 

 stone tools to produce excavations of so great magnitude. 



