CLAYS OF MIDDLESEX COUNTY. 463 



In the following table are a number of clays, the fusibility of 

 which was alone tested : 



Fusion tests on additional semirefractory clays. 



Name. Formation. Cone. 



Buff clay, Dixon bank, . .Raritan clay bed, 27 vitrified 



Retort clay, do do 27viscous 



Fine clay, do .. do 30 do 



Yellow-mottled clay, 



Staten Island Clay Co., Woodbridge clay bed, . 27 do 

 Yellow brick clay, H. 



Maurer & Son, do 27 do 



Retort clay, J. Prall,.... do 27 do 



Fire clay, 1 Ostrander Co., do 26 vitrified 



Sandy fire clay, 2 do do 29 viscous 



Buff-burning clay, No. 2 



fire clay, R. N. & H. 



Valentine, do 27 do 



Red clay, Raritan clay bed, 27 do 



Pipe clay (known as 24), 



C. S. Edgar, Woodbridge clay bed, .27 do 



Blue clay, Whitehead 



Bros., do 27 do 



NONREFRACTORY CLAYS. 



These include the great series of laminated sands and clays 

 overlying the Woodbridge fire clay, as well as some of the clays 

 found in the Raritan potter's-clay bed. In the early history of 

 the clay-mining industry in New Jersey, these beds were either 

 discarded or left undisturbed, but at the present day enormous pits 

 have been opened in them and the clay is frequently dug with 

 steam shovels, so- as to produce a sufficient supply for the large 

 fireproofing, hollow-brick, conduit and building-brick factories 

 located in this district. They fuse below cone 20. 



These clays are now dug: 1. In the Woodbridge district; 2. 

 On the north side of the Raritan river around Keasbey ; 3. Around 

 South River; 4. Around Sayreville. 



Locality. 



No. 



Woodbridge, 



9, 



do 



9, 



do 



9, 



do 



34, 



do 



24, 



do 



28, 



Sand Hills, 



53, 



do 



54, 



do 



86, 



Mill brook, 



95, 



Bonhamtown, 



98, 



South River, 



84, 



1 Sample from the upper five feet of bed in the most northeasterly opening. 



2 From a pit near the road, southwest of the preceding. 



