631
STRENGTH OE GLASS.
Comparison of strength of lights set in square frames and having a bearing along each edge, with similar lights transversely loaded, which were supported at two opposite edges only.
		Total ultimate strength.		
Description.	Thick- ness.	In frames 16" x 16".	Transverse tests, 16" wide by 16״ span.	Ratio of strength.
Rough plate		Inch.	Pounds. 123	Pounds. 68	1.9
		197	180	1.1
		360	209	1.7
	!	523	552	.95
		1,264	718	1.8
	»	2,470	1,807	1.4
Wired plate			231	251	.9
	i	517	417	1.2
		1,097	761	1.4
For the above comparison of strength, the results of the two transverse specimens 8" wide, each, are added together and placed against the mean of two tests of 16" x 16" lights in frames.
Compression Tests.
I
Nominal dimensions»
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Description.	Dimensions.			Sectional area.	Ultimate strength.	
	Height.	Compressed surface.			Total.	Per square inch.
Rough plate	 Polished plate		Inches. 3.81 3.90 4.03 4.00	Inches. 0.98 .99 1.07 1.08	Inches. 2.02 2.02 2.04 2.04	Sq. in. 1.98 2.00 2.18 2.20	Pounds. 102,500 155,400 98,200 184,800	Pounds. 51,770 77,700 45,040 84,000