126 NEW YORK STATE MUSEUM 



Hackett quarry 



Hackett Brothers, of Yonkers, have operated a quarry for several 

 years in the northern part of the main Yonkers belt. Their property 

 lies about a mile north of Dunwoodie, at the junction of Midland 

 and Central avenues, and is opened for a distance of 800 feet along 

 the course of the gneiss. 



The working face is about 40 feet high. The quarry has furnished 

 a large amount of building stone, which is its chief product. Some 

 of the larger structures in which the stone has been used are: 

 St Joseph's Seminary, Dunwoodie ; Seton Hospital, Spuyten Duyvil ; 

 St Joseph's Hospital, Yonkers ; St John's Hospital, Yonkers ; St 

 Dennis Church, Lowerre ; and public school buildings Nos. 3, 9, 10, 

 15, 18, Yonkers. Polished examples are shown in the columns of 

 the county jail at White Plains. 



The rock is characteristic Yonkers, rather fine in grain and of 

 bluish color, as seen in the quarry ledge. This color becomes more 

 of a pink on the cleavage surface of hand specimens, owing to the 

 fact that the colored feldspars are much pressed out, along the 

 foliation. The hammer-dressed surfaces are a medium gray. The 

 stone is free of spots and discolorations. 



The gneissoid foliation at this locality is quite regular in direction 

 and character. The strike is N. 30° E. and the dip vertical or 

 slightly turned to the west. Horizontal joints are well developed, 

 at an average of from 3 to 5 feet apart, permitting bench operations. 

 A second system of joints parallels the foliation, and the third 

 strikes N. 65° W. and dips 80° W. The structure is well suited to 

 the production of dimension stone. The rift, of course, runs with 

 the foliation. 



In quarrying, the stone is broken out by, black powder. Holes 

 are put down about 10 feet by a steam drill. This method naturally 

 yields a large quantity of material unsuited for building stone and 

 this finds sale for rough foundation work, particularly in macadam 

 and telford roads. There are two derricks in place. The average 

 force is about ten men. Shipments by rail are made by the Putnam 

 division of the New York Central Railroad. 



Perri quarry 



A quarry, operated by Louis Perri, is situated on the east side of 

 Central avenue, across from the Hackett property. It is just west 

 of the site of the old O'Rourke quarry, now converted into building 

 lots. The opening at this place is about 100 feet long and affords 

 a face about 30 feet high, practically unweathered to the surface. 



