No. 275. 1 S5 
equally good quality, which can be quarried, shipped and hauled at less 
expense than the stone we now import from Maine, New-Hampshire, 
Massachusetts and Connecticut. The granites of the Hudson river 
must then, soon be wrought and sent to market, and the quarries will 
become very valuable. 
II. GNEISS. 
Gneiss is the predominant rock in New-York, Westchester and Put- 
nam counties. It varies greatly in external aspect and in composition 
in different parts of the tract under investigation. Its colour is dependent 
upon the relative abundance of its constituents, which are variously co- 
loured in different localities. The feldspar is white, reddish, or of a 
bluish gray; the mica is black, brown, yellow, copper coloured, and 
white; the quartz is white, gray or smoky. In some places mica abounds 
in the rock, and it approaches to mica slate, but more commonly the 
feldspar is most abundant, and gives character to the rock. 
Much of the gneiss in the Highlands of the counties under consider- 
ation, is a hornblendic gneiss, in which the mica is wholly or in part 
replaced by hornblende. 
A range of granitic gneiss, of a light colour, passes through Putnam 
and a part of Westchester county. It extends through Carmel, near 
Pine pond, by Mahopack pond, thence southwardly, and crosses the 
turnpike from Peekskill to Danbury. Another bed extends from Boyd's 
corners in Putnam county and crosses the Peekskill and Danbury turn- 
pike about five or six miles from the former place. These beds are quar- 
ried to a small extent, for use in the vicmity; but they are too remote 
from water transport, for quarrying at present, for a more distant mar- 
ket. It is durable, of a light gray colour, easily split from the quarry, 
and easily dressed. If these strata reach the Hudson river, they are be- 
lieved to have changed so much in aspect and quality as building stone, 
as not to have been recognized as the same beds. The bluish gneiss is 
quarried at Gen. Van Cortland's quarry, near Royd Hook, two miles 
west of Peekskill. Another quarry is opened near Peekskill Landing, 
half a mile northwest. 
A range of reddish gneiss extends NNE from the point above Tarry- 
town. In many places excellent quarries may be opened, where the 
stone quarries well, dresses easily, and is beautiful and durable for archi- 
tectural purposes. One quarry is already worked to some extent in this 
range, for the New-York market, on Mrs. Eeekman's farm, about one 
and a half miles from Tarry town. Large quantities of stone are taken 
