S18 NEW YOKK STATE MUSEUM 



and south of the pit. The one objection to the deposit is that the 

 clay is overlain bj about 20 feet of yellow gravel and drift, which 

 has caused much trouble at times by caving. It would seem that 

 underground workings could be established, which would be more 

 permanent. A number of pits have been sunk in the clay, many 

 30 feet in depth, the usual diameter being 10 feet. This clay has 

 been used for a variety of products, such as architectural terra 

 cotta, common stoneware, chemical stoneware and clay pipes. 



The clay, which was of a dark gray color, was very plastic and 

 often quite smooth. At the time the samples for physical work 

 were collected the bank had caved in and no specimens were ob- 

 tainable, but the following is an analysis of it made by Dr H. C. 

 Bowen on a sample collected some years ago. 



Silica 76.50 



Alumina 15.17 



Ferrous oxid 1.34 



Lime .59 



Magnesia .11 



Soda 81 



Potash 127 



Phosphoric acid . .07 



Moisture .12 



"Water (combined) ,. 4.27 



Glencove. Carpenter Bros, have a bed of stoneware clay, fire 

 sand and kaolin on the east side of Hempstead harbor. The 

 clay is of a white and pink color, the layers being 4 inches to 1 

 foot thick, interstratified with layers of quartz pebbles. ISTearer the 

 shore this dips under a bed of the clay free from pebbles. Asso- 

 ciated with the clay is a deposit of kaolin and fire sand. The clay 

 burns a cream color. The quajtz pebbles, which contain small 

 cracks, crumble easily and seem to have been subjected to the action 

 of some alkaline solution.-^ When ground they can be used for the 

 finest grades of pottery and stoneware. The fire sand and kaolin 

 are screened and sold according to grade. 



'F. J. H. Merrill, "Geology of Long Island," Ann. N. Y. acad. sci. 1884. 



