of New-York and New-Jersey, &c. 185 
spposite Spiten-Devil, 407 ;—a height a little farther Norfh, 
but rising above the general level, 479 ;—Bompay Hook, 
two miles above Closter landing, 517 ;—bluff North of 
Bompay Hook, 549 ;—Closter mountain near Rock-land 
County, 539. 
I observed at several places on the summit of the Pal- 
isadoes, large projecting columns of greenstone, with 
from four to six well defined sides and in one or two 
instances nearly regular hexahedral prisms eight or ten feet 
in diameter, apparently extending to the base of the preci- 
pice and retaining for a considerable distance their basalti- 
torm aspect. 
Atthe termination of the Palisadoes, Tappan sea, an ex- 
pansion of the Hudson commences and extends northerly 
ten miles with an average breadth of four. A clove pas- 
sage through which winds Tappan creek, separates the Pal- 
isado table land from a mountain range that gradually rises 
north ; this chain has for four miles at its base the waters of 
Tappan sea ; the eastern side seldom exhibits precipices ; 
it is in many places elevated and cultivated—but the 
summit displaying irregular elevations is generally crown- 
ed with wood. Greenstone in no way differing from the 
rock of the Palisadoes is exclusively the summit rock in 
place. .The western side of the mountain is in general 
steep, rocky and wood-clad. Adjacent to Tappan creek 
an excavation is seen extending horizontally into the 
greenstone rock of the mountain about 1000 feet, made in 
searching for silver, but the vein was not found sufficiently 
00d to be worth pursuing. Red sandstone is extensively 
quarried on the eastern side of the mountain at various el- 
evations, 
ack. Land bordering Tappan sea, that embraces good 
guarries of freestone is valued at 1500 dollars the acre.— 
he mountain chain ranges in the back ground to the north- 
west of Nyack, presenting moderate elevations—it — 
Sweeps forward to the east bounding Tappan sea on its nor- 
