244 
GEOLOGY OF THE THIRD DISTRICT. 
Scratches and Furrows upon Water-worn Rocks. 
The worn surfaces of rocks, and the scratches in determinate directions which they often 
present, are now an interesting subject of geological inquiry, in the greater part of all North¬ 
ern Europe and in this country. One of the best localities in the third district for observing 
these phenomena, is at the limestone quarry of Mr. Marcellus, commonly called Schelpin- 
town, situated about two and a half miles to the northeast of Amsterdam. The surface of 
the rock is covered with soil and earth, which, when removed, show a water-worn surface 
with two or three sets of scratches, exhibiting great regularity, and having a common direc¬ 
tion towards the east, one set of which is about eight degrees south. The scratches, includ¬ 
ing furrows, were generally from a mere line to one-fourth of an inch wide, and from one to 
two-tenths of an inch and more in depth. 
78. 
Specimen from Marcellus' quarry. 
No. 1, has no parallel on the specimen: It is evidently of an older date than some of the others. 
2. This, with 3 and 4, belong to the same set. It shows the effect, when examined, of a tremulous movement. 
3. Lines which are slight, and some of them not continuous through the specimen. 
4. This exhibits finely the effect of the vibratory movement, and resembles lace. 
5. is a scratch of an older date : It passes under, or is crossed by No. 4. 
6. Part of No. 2, magnified to show the tremulous motion which produced a succession of fine nicks. 
