489
CEMENT.
Brand.	Description.	Loss in heating from 110° C. to redness.		
		Total.	PI20.	C02.
Whitehall		Reground material from a 4״ cube, set in	Per cent. 14.79	Per cent. 10.37	Per cent. 4.42
	air 24 hours, reground and retempered, set in air 35 days.	2.51	1.09	1.42
		22.24	3.24	19.00
Newark and Rosen-		do		4.74	1.22	3.52
dale.	Exposed to the air 28 days		7. 20	2.06	5.14
	Reground material from a briquette set	11.26	4.46	6.80
	in air 28 days. Reground material from a briquette set	15.10	9.34	5.76
Storm King		in water 28 days. Material from a 2" cube set in air 8	14.57	5.88	8.69
	months, taken within 10.״ from the surface. From same cube as above, taken below	8.22	5.62	2.60
	".25 from the surface.			
The material used in the determinations given in the next table was taken from a series on retarded sets, in which the cement was agitated at 2-hour intervals, and put into the molds at the times stated in the column headed “Hours retarded.” The original quantity of water used in the mixing was 28.6 per cent, more water being added at intervals. Four-inch cubes were made and set in air 35 days. The material was then reground and the determinations made.
			Loss in heating—			
	Brand.	Hours retarded.	To	From 110° C. to redness.		
			110° C.			
				Total.	H20.	co2.
			Per cent.	Per cent.	Per cent.	Per cent.
		8	7.40	13.77	11.90	1.87
		12	9.96	15.02	11.37	3.65
		16	10.08	16.64	13.22	3.42
		20	11.04	17.18	13.48	3.70
		24	12.80	16.51	13.17	3.34
		30	14.48	17.49	13.79	3.70
		36	15.36	16.77	13.42	3.35
		40 48 56 64	16.00 15.52 16.92 14.08	17.70	14.70	3.00
						
						
						
Additional determinations on loose material from the barrels were made about seven months subsequent to the determinations shown in preceding tables, with the following results:
Brand.	Loss on heating from atmospheric temperatures to redness.		
	Total.	H20.	C02.
	Per cent. 1.37 1.27 4.36 5.14 7.36	Per cent. 1.12 .99 1.46 .56 .17	Per cent. 0.25 .28 2.90 4.58 7.19