66 ECONOMIC GEOLOGY. 
showing very distinctly on surfaces slightly weathered. There is likewise considerable 
included quartz. The galenite occurs in small blotches, showing a tendency to form 
in the centre of quartz nodules. It is unusually dark-colored and splendent, plenti- 
fully sprinkled with minute crystals of pyrites. The entire quantity of ore is slight. 
Rumney. Upon porphyritic gneiss in the north-east part of the town is a vein 
owned by George L. Merrill. The metalliferous mass is 12 feet wide, exposed in an 
excavation 14 feet deep. The walls dip 80° N. 70° W., enclosing a soft feldspathic 
rock with some quartz. Two kinds of trap rocks are situated in the vein, dark- and 
light-colored. The galena and blende follow reticulating veins of quartz, inter-pene- 
trating the general mass. The galena contains a trace of gold, and 1.95 oz. of silver 
to the ton. 
North Woodstock. Wandsome specimens of galena, blende, and pyrites have been 
shown us from Horner’s farm. Some work has been done in the way of opening 
the vein. The galena shows a trace of gold, and 7.84 oz. of silver to the ton. 
flooksett. Upon the quartz ridge south-west from the Pinnacle is a small lead vein. 
The best part of it shows three inches width of galena. This is hardly sufficient for 
mining. 
Other localities are in Bath, Haverhill, Epsom, Nashua, Lyndeborough, Dunbarton, 
Tamworth, Sandwich, Lyme, and elsewhere. 
TIN. 
Tin ore has been discovered in Jackson in such quantity and so re- 
lated that miners have thought a good vein of it might be developed by 
diligent exploitation. From time to time prospectors have searched the 
neighborhood, particularly in Maine, where greater success has been met 
with than in our state. Dr. Jackson was greatly interested in the sub- 
ject, particularly as this was the first discovery of the ore in so great 
quantity in the country. From investigations made about 1840, the 
following conclusions have been derived: 
The rock of the country is a mica schist dipping 30° N. E. by E., with veins or 
elvans of granite crossing it. The ore is cassiterite, occurring in four veins, making a 
triangular space of 200 to 300 square feet by their intersection. No.1 is mostly com- 
pact ore, eight inches in the widest part, yielding 30 per cent. of tin, associated with 
chalcopyrite and mispickel, and the course is N. 7° E. No. 2 contains crystalline ore 
with mispickel, half an inch wide, running N. 80° E. in granite. This ore crosses 
the others, like the horizontal line in a figure 4. No. 3 is a compact ore in mica 
schist, from half to three quarters of an inch wide, running N. 56° E. No. q is nearly 
parallel to the last, from a half to an inch and a quarter wide. No. 1 is cut by a dyke 
of trap. The rock near the veins contains from two to ten per cent. of tin. The 
other minerals found with the cassiterite are mispickel, pharmacosiderite, chalcopyrite, 
