Geology of Massachusetts. 17 
The Westford and Pelham granite is connected with an imperfect 
kind of mica slate, in which it seems to form beds, or Jarge protru- 
ding masses. In the same mica slate at Fitchburg, a little south of - 
the village, is a large hill of the same kind of granite. This is quar- 
ried, though not extensively, on account of the little demand for the 
stone. This single hill, 300 feet high, and nearly a mile in cireum- 
ference at its base, might furnish enough to supply the whole State 
for centuries. Some of it, however, is too coarse for architecture. 
The manner in which the granite is usually split out of the quarries 
is this. A number of holes, of a quadrangular form, a little more than 
an inch wide, and two or three inches deep, are drilled into the rock, at 
intervals of a few inches, in the direction in which it is wished to separate 
the mass. Iron wedges, having cases of sheet iron, are then driven at 
the same time, and with equal force, into those cavities; and so prodi- 
gious is the power thus exerted, that masses of ten, twenty, thirty, 
and even fifty and sixty feet Jong, and sometimes half as many wide, 
are separated. ‘These may be subdivided in any direction desir- 
ed ; and it is common to see masses thus split, till their sides are less 
thes a foot wide, and their length from ten to twenty feet. In this 
state they are often employed as posts for fences. 
Respecting the price of the granite from the quarries that save 
been described, I have not been able to obtain much informa- 
tion. At Fitchburg, I was told that it was sold at the quarries, well 
dressed, at forty cents the superficial foot; and at sa at forty- 
five cents. 
The cost of Gearacring and fine dressing eranitte} Boston, in the 
style of the Tremont House, I have been credibly informed, is about 
thirty cents the superficial foot. Ordinary work, however, is from 
twenty-five to thirty cents; and not unfrequently, even as low as 
twenty cenis. 
Concord and Hallowell granite cost about fifty cents per foot in 
Boston ; but are now little use 
Posts for store-fronts, cost about thirty-four cents per foot in Bos- 
ton. The columns of the Hospital were hia for about one dollar 
per foot. 
To show how rapidly the price of granite has fallen, I would state 
on the authority of a respectable architect in Boston, that the cosh 
of the blocks of the Quincy granite for the Bunker Hill monument, 
delivered at Charlestown in a rough state, was thirteen cents, three 
mills, per foot ; and the cost of the unhewn stone for the church built 
Von. XXII.—No. 1 3 
