METALS AND THEIR ORES. 35 
Heavy spar, fluor, pyrites, copper pyrites, and blende occur in small 
amount. For the depth of 60 feet, the galena constitutes a sheet averag- 
ing 12 inches wide. Below this level the ore is more crystalline; and the 
lode clearly discernible to the depth of 220 feet. There are five levels in 
the mine, and two shafts; and Prof. Vinton estimated that 40,000 gross 
tons of ore were actually in sight, which may be concentrated to 4,000 
tons of dressed ore worth $94 per ton. The ore in sight on the first 
level was 1,500 cubic yards, and 10,000 upon the fifth or lowest. Under- 
ground, the vein has been explored a distance of 400 feet. The best part 
of the ore is situated in a chimney, nearly vertical, but inclined south- 
west, and averaging a width of 100 feet on the several levels. 
Dr. Stevens mentions a mass of auriferous quartz parallel to the lead 
seam on the south-east side, varying in width from one yard at the 60- 
feet level to 5 feet at the 150-feet level and lower down. Working tests 
of the value of the quartz gave $11 of silver and $9 of gold to the ton. 
He also refers to the probable existence of a narrow seam of tetrahedrite 
continuous with the main galena belt. This mineral is exceedingly rich 
in silver, the maximum being $4,610.62 to the ton. The galenas average 
“about $60 to the ton, and have been the principal resource from which 
bullion has been obtained. 
The mine is well equipped with the necessary appliances for working, 
and smelting or reducing works are nearly or quite ready for use. The 
community have differed in opinion respecting the value of the property. 
It is obvious that heretofore the aim of the managers has been specula- 
tive. Most of the openings in the neighboring towns are of little value. 
We have the same rock in New Hampshire; and whenever indications 
are found similar to those manifested at Newburyport, exploration may 
lead to remunerative mining. 
Maps oF THE MINING REGION. 
Before beginning a description of the copper mines, I will call atten- 
tion to two maps. The first is a geological delineation of the Ammo- 
noosuc mining district, and is placed for convenience in the atlas, and 
referred to upon page 280 in Volume II. It is designed to embrace the 
final results of all our topographical, geological, and economic studies, pre- 
pared for the engraver and colored at the latest possible date. The scale 
