64 ECONOMIC GEOLOGY. 
in the order given. In such of the rock thrown out as was visible, they do not occur 
any of them in large nodules, but scattered in specks through the gangue, and in such 
form that much would be unavoidably lost in the necessary process of mechanical 
concentration. A fair average sample, taken from the accessible output of the 
«« Banks shaft,” of such rock as would have to be worked, crushed without any separa- 
tion of ore from gangue, showed,—in the hands of a professional assayer,—gold, 0.01 
0z., silver, 3 0z., to the ton of 2000 lbs. 
Shelburne Lead Mine. About 14 miles west of Shelburne station, on the Grand 
Trunk Railway, Lead Mine brook empties into the Androscoggin on the north side. 
Following up this brook 14 miles, a branch comes in from the west through a narrow 
gorge on the eastern declivity of Mt. Hayes. At the junction of the two brooks are 
the ruins of ore-separating works, run by water-power, and of three log-cabins. We 
are here at an elevation of 130 feet above the Androscoggin. Taking the western 
branch, a further walk of about forty rods brings us to an abrupt turn in the brook at a 
right angle, the stream coming down over the cliff, which forms the northern wall of 
the gorge, in a cascade thirty feet high. The mineral vein runs along the bottom of 
the gorge, much of its course in the very bed of the stream. At the abrupt turn above 
mentioned the first opportunity to attack it above water-level has been availed of to 
drive an adit westerly into the mountain upon the vein itself. The adit is 5 feet by 4, 
and extends about 30 feet. Within a distance of fifteen rods from the adit three shafts 
have been sunk in the bottom of the narrow gorge, so close to the brook, and their 
mouths so little above its level, that the most ordinary rise would flood the entire 
workings. This metalliferous deposit has been worked at several different periods by 
different companies, and the adit was an after-thought of a later company. One of the 
shafts is stated to be 80 feet in depth, and another 275, and to have proved the vein 
eight feet wide at the lowest point reached, carrying in places six inches solid ore. If 
this be so, the vein at the surface is evidently ‘‘a pinch,” and the adit could have given 
no practical vantage without the sinking in it of awinze. At the present not only 
are the shafts flooded,—they were this probably twenty-four hours after the pumps 
stopped,—but the floor of the adit is under water, so that it is impossible to learn 
much of the deposit without a considerable amount of actual work being done. The 
vein, which is one of segregation, has a strike N. 75° E., and a dip 70° N. 15° W. 
At its surface its width ranges fram two to six inches. The gangue is quartz, which 
on the hanging-wall is quite pure, while on the foot wall, which is ill defined, it grades 
into a micaceous gneiss. The chief ore carried is galenite, associated with a very 
dark blende, and a notable amount of pyrites. The galenite seems to be invariably 
mixed with these ores, while on the other hand the pyrites occurs in some places unas- 
sociated. A sample of galenite with pyrites, gave, in the hands of a professional 
assayer,—gold, none; silver, 15.06 oz. to the ton of 2000 Ibs. This ore was almost 
free from gangue, and may be considered a favorable sample. From the fact that so 
many parties have worked this,—one of the historical mines of New Hampshire,— 
always with the result of abandonment, it would seem a fair inference that however 
