366 On the Bristol Copper Mine. 
ported on by Prof. Silliman, Senior, of Yale College, in 1839, 
and upon this report funds, to a small amount, were: obtained in 
England for prosecuting the work.* But the adventurers being 
unable to sustain the enterprise, the explorations were subse- 
quently continued by Mr. L. C, Ives, who erected a small steam 
engine, and sunk the present engine shaft in the sandstone to the 
20-fathom level. During this time, and prior to 1847, consider- 
able shipments of the ore had been made to England, but exactly 
what quantity we have no means of ascertaining. It appears, 
however, from the information obtained from the last named pro- 
prietor, that it could not have been less than 100 to 125 tons. 
It was not, however, until 1846-7, that the mine was opened 
and worked to any considerable extent. At that time it passed 
into the hands of Mr. Hezekiah Bradford and _ his associates. 
~~ Since that period a large amount of money has been expended 
here, and over eighteen hundred tons of copper ore have been 
raised and sold. In 1851 the management of the mine passed 
into the hands of Mr. Henry R. Sheldon, as agent for the present 
owners. . Sheldon (who is still the manager) has had the 
satisfaction of seeing the mine rise from a state of great depres- 
sion in its affairs and prospects to a condition of prosperity and 
encouraging profits, with the certainty that by a judicious and 
moderate outlay, it can be made to return the whole cost of its 
plant and extraordinary expenses, with a wide margin of profit to 
the adventurer. 
The value of the “ great flucan” in ore appears from the aver- 
age of all the trials which have been made upon it for a long period, 
including the actual results of stamping and crushing to be over 3 
per cent of ore having 30 per cent copper. In a calculation made 
upon the probable future product of the mine, it is assumed that 
the average yield will be 24 per cent. The material composing 
the flucan is so soft and easily removed that no gunpowder is 
required in mining it. As soon as it is exposed to the action of 
air and moisture it runs as the miners express it and becomes 
like a micaceous clay. It weighs a little more than 150 pounds to 
the cubic foot. In a careful examination of the fresh material, it 
is not difficult to see that it is chiefly the feldspathic portion of the 
original material which has undergone decomposition. The out- 
line of the feldspathic portions is plainly discovered by the friable 
mass of mingled silica and clay of a white color loosely filling 
the space occupied by the feldspar. Small garnets, of a deep red 
color, and small black tourmalines are constantly to be seen when 
the material is washed—being apparently almost the only sub- 
stances beside the vitreous ore of copper which have escaped the 
powerful decomposing influence which has produced this great 
zone of altered material. : 
— was in confirmation of one made in October, 1838, by Prof. C. U. 
en 
* This 
Shepard, which we have never seen. 
