CLAYS OF CAMDEN COUNTY. 405 



Chemical Analysis of brick mixture, Fish House. 



Silica (Si0 2 ), 65-53 



Alumina (A1 2 3 ), 17.21 



Ferric oxide (Fe:0 3 ) , 5.23 



Lime (CaO), 0.95 



Magnesia (MgO), 0.31 



Potash (K2O), 2.84 



Soda (Na-O), 0.96 



Loss on ignition. 4.54 



Total, 97-57 



This shows a high percentage of total fluxes, and it is doubtful 

 if the clay could be heated to cone 10 or 12 without fusing. 



Pleistocene clay loams are found overlying - the Clay Marls at 

 several localities in the county, and are usually mixed with the 

 latter in the manufacture of brick, although the loam by itself is 

 of little value for brickmaking in most cases, because of its low 

 plasticity and tensile strength, and its porous-burning character. 

 Besides this it often contains pebbles which should either be 

 crushed or carefully removed by screening, for otherwise they 

 tend to split the brick in burning. 



Clay-working Industry. 



Common building brick are made in large quantities at Fish 

 House, by Hatch & Sons, at City Line station, Camden, by Budd 

 Brothers, and at Collingswood, by J. C. Dobbs. The bricks in all 

 cases are made by the stiff-mud process. Some of these yards 

 have been in operation for a considerable period. Dry-pressed 

 front brick of a number of shades and colors have been made by 

 the Eastern Hydraulic Press Brick Company, at Winslow Junc- 

 tion, since 1890 (PI. XLH, Fig. 2), the clays being dug at various 

 localities. 



Draintile are made at Collingswood by J. C. Dobbs. Red 

 earthenware and stoneware are produced at Haddonfield by C. 

 Wingender & Bro., the raw clays being derived in part from Cam- 

 den county and in part from the South Amboy district. A factory 

 for the manufacture of sanitary ware is also in operation at Cam- 

 den. It is now controlled by the Camden Pottery Company. 



Tests of bricks from this county compare very favorably with 

 those from other localities. 



