SURVEY OF THE ISLAND OF NEW-YORK, 
585 
west, and the strike is N 35° E. At Nos. 2 and 3 (vide PI. 37, fig. 2), the drift furrows are 
large and deep ; direction N 35° W ; and again at No. 1, they are also distinct, and have the 
the same direction. 
At No. 2, PI. 37, which is about two hundred feet north of that represented at No. 4, is a rock 
of gneiss, which is the highest point in the neighborhood. The top of this rock presents a sur¬ 
face in a northerly and southerly direction of sixty feet, and east and west of eighty feet, and 
is by estimation seventy feet above the tide waters of the Hudson, and from three hundred to 
four hundred feet distant. Over the whole surface, and at an angle of 60°, and 120° with 
the strike, are drift grooves from half an inch to an inch in depth, and from forty to sixty 
feet in length, and from one to six inches wide, and remarkably distinct. The direction is N 
35° W, and strike N 25° E. 
In another rock at 3 (PI. 37) about fifty feet north of the last, and of twenty feet less elevation, 
the grooves are three inches deep, and from five to seven inches wide. Direction of the 
grooves N 35° W; strike N 25° E, and the dip nearly vertical. 
About four hundred to five hundred feet northwest of 3, PI. 37, is the gneiss rock on the banks 
of the river, represented at No. 1, where the rock extends to the water and dips beneath it, and 
again disappears under the soil about ten feet from the water, and six feet above its level. The 
scratches are as distinct as any I have ever seen. Direction N 30° to 35° W, and cover a 
surface north and south of thirty to fifty feet. 
Again on the heights, three hundred to five hundred feet farther north, and in a northeasterly 
direction from No. 1, at John K. Howland’s country seat, on the rocks a few rods, say twenty, 
north of his house, are to be seen similar grooves, and running in the same direction. 
Again at the place next north of Howland’s are similar grooves, running N 25° W. These 
are on the precipice of the rock, eighty feet above the water, and three hundred feet distant. 
Again on the water’s edge, opposite the last, grooves are seen in direction N 30° W, and 
extending two hundred feet north and south on the shore. 
From Howland’s, six hundred or eight hundred yards north, the gneiss dips to the west 80°, 
and the grooves are quite abundant. One of these measured six feet long, eight inches wide 
and four inches deep. Boulders of greenstone and sandstone are abundant, all along the 
shore. 
From Howland’s northward to Webber’s, the last place corresponding to lOlst-street, the 
gneiss rock is constantly in sight on the shore, and during almost the whole of the distance 
covered with grooves, running in direction varying from N 30° to N 45° W, but rarely more 
than N 30° or 35° W. 
Ninth avenue. 
Ninth avenue commences a little below 14th-street, and is graded upwards to 23d-street; 
sparsely settled to 16th-street, and densely from 16th to 22d-street, or to the block above 
Chelsea square. 
Geol. 1st Dist. 
74 
