CEMENT---SET AT DIFFERENT TEMPERATURES.	577
RiSUMfi OF RESULTS ON SPECIMENS SET IN AIR AT 0° F. 3 MONTHS, AND IN ADDITION 1 DAY AND 7 DAYS, RESPECTIVELY, AT 70° F.
Brand.	Compressive strength per square inch, specimens set in air at 0° F. 3 months, and in air at 70° F.—	
	1 day.	7 days.
	Pounds. 1,720 497 703 1,210 624 237 241 478 276 347 274	Pounds. 2,690 1,010 1,290 2,350 1,520 558 340 810 457 558 516
		
		
		
		
		
		
		
		
		
		
		
	600	1,100
		
COMPARISON OF RESULTS ON SPECIMENS WHICH SET IN AIR AT BOTH 0° F. AND AT 70° F. WITH THOSE WHICH SET IN AIR AT 70° F. ONLY.
Compressive strength per square inch.	
Intervals at 0° and	Interval
70° F.	at 70° F.
Pounds.	Pounds.
3 mos. + 30 days.	30 days.
3,620	4,570
2,520	3,900
1 mo. -f 30 days.	30 days.
3,460	4,570
1,400	1,960
1,680	2,520
3 mos. 414 ־ days.	14 days.
1,310	1,970
ci 2,450	3,780
1,730	3-, 330
648	1,160
1,020	800
579	808
832	744
1,771	2,509
Brand.
Star...............
Alsen..............
Star...............
Star, 1:1 mortar...
Storm King.........
Star, 1:1 mortar...
Alsen..............
Josson.............
Steel .............
Bonneville Improved
Hoffman............
Norton.............
Means........
Approximate.
H. Doc. 508-----37