CAPTAIN NOBLE AND ME. E. A. ABEL ON PIEED GUNPOWDEE. 
151 
Experiment 64. — Fired 5960 grs. (386-2 grms.). 
Quantity of gas . 106,625-0 cub. centims. 
Temperature of gas 16 0, 55 C. 
Barometric pressure . 758-2 millims. 
Experiment 65. — Fired 6840 grs. (443-23 grms.) P. in cylinder No. 7. This charge 
filled the cylinder nearly quite full. Cylinder, on firing, cracked between the firing- and 
crusher-plugs. Crack about -5 millim. wide. Report very loud. 
^ a Crush, copper Pressure 
cylinder. in tons. 
•900 -0833 -1833 -156 33-4 
Experiment 66. — Fired 6840 grs. (443-23 grms.) P. In about a second after firing 
the gas made a fizzing sound, and in about another second escaped by blowing out the 
gauge-plug with a loud report. Lower threads of the screw on the crusher-plug washed 
away by the escape of the gas. 
£ ^ a Crush, copper Pressure 
cylinder. in tons. 
•900 -0833 -0833 -145 31-6 
Experiment 67. — Experiment on mode of detonating a charge. 
Experiment 68. — Fired 6840 grs. (443-23 grms.) R. L. G. Cylinder and all parts 
perfectly tight. Residue and gas collected. Observed that the deposit had apparently 
not contracted much. 
On the firing-plug were several congealed drops of deposit like icicles, and on the 
surface below spots, which had apparently dropped from above, were visible. 
Surface of deposit dark grey, almost black. 
Fracture olive-green, with frequent spots of brilliant yellow of the size of a pin’s 
head. 
Top part of deposit put in separate bottle from bottom part, each sample being 
ground and mixed carefully in an atmosphere of dry nitrogen. 
§ a Crush, copper Pressure 
cylinder. in tons. 
•900 -0833 -0833 -168 35-6 
Experiment 69, May 29, 1873. — Fired 6840 grs. (443-23 grms.) F. G. Cylinder &c. 
perfectly tight. On opening the cylinder, found white crystals deposited on firing-plug. 
Deposit very dark and more greasy than usual. 
Fracture dark grey, with only few spots of yellow. 
Deposit first taken did not heat ; but there was great difficulty in getting it to grind 
in an atmosphere of dry nitrogen. 
The portion we succeeded in grinding was sealed in test-tube marked experiment 69a. 
Unground portion sealed in test-tube marked B. Bottom portions of the deposit, 
when exposed to the air, changed with great rapidity to a bright yellow on the surface, 
