HELICAL SPRINGS.	385
Helical Springs, Double Coil, for 12-inch Mortar Carriages.
Twenty springs from lot of 58 received June 12, 1901.
......inches.. 9.10
.........do...	1.74
.........do...	14.30
........do...	.96
85 pounds 0 ounces
.....inches.. 5.55
.........do...	1.24
.........do...	13.35
.........do...	.57
34 pounds 12 ounces
DESCRIPTION OF ONE SPRING.
Outside coil, left-hand spring:
Exterior diameter of coil...............................
Diameter of bar.........................................
Height of spring unloaded...............................
Distance between coils..................................
Weight..................................................
Inside coil, right-hand spring:
Exterior diameter of coil...............................
Diameter of bar.........................................
Height of spring unloaded...............................
Distance between coils..................................
Weight..................................................
COMPRESSION TESTS.
Description.	Height.	Load sustained. '	Remarks.
	Inches.	Pounds.	
First spring		12.25	17,500	
	12.20	18,800	
	9.75	45,700	Closed down.
	11.85	18,000	
	12.25	14,100	
Second spring		12.25	15,700	
	12.03	18,000	
	9.75	46,600	
	9.70	49, 300	(dosed down.
	9.75	45,700	
	11.68	18,000	
	12.25	12,350	
Third spring		12.25	17,300	
	12.18	18,000	
	9.75	45,400	
	9.72	45,700	Closed down.
	9.75	44,450	
	11.82	18,000	
	12.25	13,560	
■ Fourth spring		12.25	16,700	
	12.14	18,000	
	9.75	45,800	Closed down.
	11.75	18,000	
	12.25	12,740	
Fifth spring		12.25	17,400	
	12.20	18,000	
	9.75	45,700	Closed down.
	11.83	18,000	
	12.25	13,620	
i Sixth spring		12.25	17,160	
	12.17	18,000	
	9. 75	45,800	Closed down.
	11.75	18,000	
	12.25	13,200	
This spring was closed down and so remained for a period of 41 hours, after which the			
results were as follows:			
	9.78	44,500	
	11.70	18,000	
	12.25	12,360	
	11.78	18,000	
	9.75	45,700	Closed down.
	11.71,	18,000	
	12.25	12,240	
Seventh spring		12.25	15,760	
	12.00	18,000	
	9.75	43,400	
	9. 65	45,100	Closed down.
	9.75	42,300	
	11.65	18,000	
	12.25	11,800	
H. Doc. 508-----25