STRENGTH OF GLASS.
632
Transverse tests of glass from Watertown Arsenal storehouse. Double thick, blown glass.
Dimensions.		Span.	Ultimate strength.	
Width.	Thickness.		Total.	Modulus of rupture per square inch.
Inches.	Inch.	Inches.	Pounds.	Pounds.
8	0.105	8	49	6,670
7.97	.122	8	68	6,880
7.95	.103	16	27	7,680
7.95	.112	16	20	4,810
7.96	.116	24	20	6,720
7.98	.120	24	20	6,270
Glass from the Watertown, Mass., public library, stack floor. Rough glass set on rectangular iron frames.
Loads applied at the center on an iron follower 2" x2" with £׳' thickness of wet cardboard cushion.
Dimensions of glass.			Dimensions of frames, in the clear.		Ultimate strength.	No. of frag-merits.
Length.	Width.	Thickness.	Length.	Width.		
Inches.	Inches.	Inch.	Inches.	Inches.	Pounds.	
35.50	17.75	0.50	34.60	17	514	7
35.40	10.75	.59	34.60	9.88	757	4
31.30	17.90	.51	■ 30.30	17	547	6
19.65	17.75	.43	18.65	17	469	8
Tested with the smooth surface of the glass uppermost.