Specimens as much as eighty feet long have been taken out and
transported great distances. The quarrying is done by drilling a series
of small holes, six inches or more deep and almost the same distance
apart, inserting steel wedges along the whole line and then tapping each
gently with a hammer in succession, in order that the strain may be
evenly distributed.
A building material that came into use earlier than granite is known as
freestone or sandstone; although its first employment does not date back
further than the erection of King's Chapel, Boston, already referred to
as the earliest well-known occasion where granite was used in building.
Altogether the most famous American sandstone quarries are those at
Portland, on the Connecticut River, opposite Middletown. These were
worked before the Revolution; and their product has been shipped to many
distant points in the country. The long rows of "brownstone fronts" in
New York city are mostly of Portland stone, though in many cases the
walls are chiefly of brick covered with thin layers of the stone. The
old red sandstone of the Connecticut valley is distinguished in geology
for the discovery of gigantic fossil footprints of birds, first noticed
in the Portland quarries in 1802.
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