16 A GEOLOGICAL HISTORY. 



and runs through the middle of the Island to Spuy- 

 tenduyvel creek ; the same rock runs through 

 Westchester County, and is seen on the other 

 side of Kingsbridge, and thence along the river 

 toward Yonkers, especially, at Mr. Delafield's 

 farm, where there is an extensive quarry, at East 

 and Westchester,* at Greenburgh, at Singsing, and 

 at Verplanck's point : a coarse marble for building 

 is worked at Singsing by the prisoners. A quarry 

 was opened at Kingsbridge, some years ago, which 

 proved unprofitable. Lime has been burnt from 

 this Limestone, but as it will not slack quickly, but 

 first crumbles up in small grains, it has been discon- 

 tinued for fine work.f 



There was a few years ago, at the south end of 

 this formation, on a by-road, leading from the 

 main road, to the North river, a spring or nat- 

 ural fountain of pure cold delightful water, 

 which gushed from this rock, and emptied in a 

 natural trough of the same rock, within 2 feet of 

 the level of the road ; this trough was large enough 



* The Merchants' Exchange in Wall street which was burnt down in 

 the great fire of 1835, was built of the Westchester Marble, (Limestone,) 

 the chafts of the columns were at least 24 feet in height and were of one 

 piece. The new Exchange is built of Sienite called CLuincy Granite. 



t When time is allowed, for lime made from this marble to slack per- 

 fectly, it answers well for strong work, and it has also, been extensively 

 used for agricultural purposes. 



