MAGNESIA BRICKS AND OXYCHLORIDE CEMENTS. 167 



"The following formula has been found suitable for window-caps, 

 sills, steps, etc. The quantities specified will make 1 cubic foot of 

 stone. 



100 pounds of beach sand, cost $1.00 per ton at the works $0.05 



10 of comminuted marble, cost $5.00 per ton at the works 0.02J 



10 of Union cement (oxide of magnesium) . 50 



10 " of chloride of magnesium in solution, 20 Baume" .02 



130 " yielding 1 cubic foot of molded stone $0 . 59 J 



"The labor, depending somewhat on the design as regards the degree 

 and character of its ornamentation, will vary per cubic foot from 20 

 to 25 cents, making total cost of 1 cubic foot of finished building-block 

 79^ to 84^ cents. This price may be reduced 10 to 15 cents per cubic 

 foot by incorporating large pebbles and small cobble-stones during 

 the process of molding. 



"For foundations and other plain, massive walls, the proportion 

 of cement may be very considerably reduced and the quantity of cobble- 

 stones increased." 



References on oxychloride cements, Sorel stone, etc. 



Ebel [Magnesia cement concrete for use in mines]. Zeits. angew. Chemie, 

 vol. 15, p. 44. Abstract in Journ. Soc. Chem. Industry, vol. 21, p. 175, 

 1902. 



Gillmore, Q. A. Practical treatise on Coignet-Beton and other artificial 

 stone. 1871. 



Luhmann, E. Magnesia cement. Chem. Zeitung, vol. 25, Report 345. Ab- 

 stract in Journ. Soc. Chem. Industry, vol. 21, p. 118. 1902. 



Preussner, L. Magnesia cement. Thonindustrie Zeitung, vol. 25, p. 2115. 

 Abstract in Journ. Soc. Chem. Industry, vol. 21, p. 257. 1902. 



Schorr, R. The briquetting of minerals. Engineering and Mining Journal, 

 vol. 74, p. 673. Nov. 22, 1902. 



