and
from Twenty-fourth street in the middle, to Sixtieth street on the
north. The Croton Aqueduct is mostly built of granite quarried in Tenth
avenue near Forty-eighth street.
Granite
abounds in Rockland and Orange counties ; it occurs in beds, veins, and
irregular masses, forming hills, and often the tops of mountains.
The
fine-grained varieties of granite are best for economical uses. When
granite contains distinct crystals of felspar, it is called porphyritic
; when the ingredients are blended into a finely granular mass, with
imbedded crystals of quartz and mica, it is called by French writers, eurite. A granular mixture of quartz and felspar is called pegmatite.
In
England, Cornwall is particularly celebrated for its gTanite ; the
obelisk from the Lamorran quarries, twenty-two feet high, which was
exhibited at the London Exhibition, was twenty-one tons in weight, and
of a coarse grain, and another, from Cornseco granite, weighing
thirty-one tons, and"eighteen feet high, were beautiful specimens of
this useful rock. They were each wrought from 3. single block of
granite, and were remarkable for extreme fineness and closeness of
grain, and the delicacy of finish which was thereby obtained.
The
granite column of Cheesewing granite, the property of the Prince of
Wales, near Liskeard, in Cornwall, was likewise a magnificent piece. It
was thirty feet high.
The bust and pedestal of blue Peterhead granite was also an interesting specimen of its kind.
Swedish
granite has been known for many centuries ; it is obtained from
extensive quarries on the island of Ma-leuva, on the west coast of
Sweden. It bears a high polish
