Richards.] 202 [November 18, 



to prove the vicinity of a thick and perhaps very extensive lead de- 

 posit. In one of these pits, on October 10th or thereabouts, the 

 vein was found, the lead being only about one inch in thickness. At 

 this time a party consisting of Prof. Ordway, Mr. J. W. Revere, and 

 myself made a trip to the mine, where we found the exposed vein to 

 consist of a streak of lead one inch in thickness, lying against the 

 south wall of the crevice, which was elsewhere filled with gangue to 

 a thickness of seven feet, but no effort had been made to reach the 

 north wall. This error was pointed out and within a few days we 

 heard that a streak of lead ten inches thick had been found against 

 the north wall of the vein. 



The gangue which fills up the intermediate portion of the crevice 

 is of a green color and is probably quartz and serpentine, or, as Mr. 

 Burbank has suggested, quartz, feldspar and epidote. Its composi- 

 tion has not yet been ascertained. The rock which lies on either 

 side of the vein differs from the country gneiss; it is crystalline and 

 free from mica, being perhaps a trap rock ; it is however much decom- 

 posed and rusty on the surface and contains occasionally specks and 

 cavities filled with galena. On the north side there is probably not 

 over five feet of this rock, if there is any of it between the vein and 

 the gneiss, but on the south side the decomposed galena bearing-rock 

 extends to a thickness of eighty or one hundred feet, before the 

 gneiss is reached. 



About the 1st of November another pit was sunk in the direction 

 of the vein to the west of the pit just mentioned, and the galena was 

 there found three and a half feet in thickness. The opening of the 

 vein on this enlarged spot shows the thickness the vein may be ex- 

 pected to occasionally assume. The mass as now visible is about one 

 foot thick at the eastern side of the pit; it widens immediately to 

 three feet and a half in thickness and then, at the western end, nar- 

 rows again to about two and a half feet. I think it highly probable 

 that it widens as it goes downward, but I have no means of knowing. 

 The southern face however dips to the south while the vein seems to 

 dip steeply to the north. Word has just been received that another 

 opening from one hundred to one hundred and fifty feet to the west 

 has exposed the vein again, where the thickness is said to be one foot. 

 A specimen of galena has also just been received at the Institute of 

 Technology purporting to come from an opening, situated upon the 

 Merrimac river, about two miles distant from this vein. With a view 

 of ascertaining the value of the mass which is now lying in the 



