CAPTAIN NOBLE AND MR. F. A. ABEL ON FIRED GUNPOWDER. 
153 
Hence the heat communicated to the gun raised gun and) 
water through / 
4°-85 F.=2°-694C. 
Experiment 74. — Exposed four crucibles filled with deposit from experiment 36 to 
most intense heat of one of Siemens’s gas-furnaces ; one crucible uncovered, the rest 
covered. Temperature estimated at 1700° C. A portion of the residue spirted imme- 
diately and then became quiet. On removal from the furnace half an hour afterwards, 
a little vapour was observed coming from the crucibles. Their contents were perfectly 
liquid, setting at about 700° or 800° C. 
The colour of the contents when cool was a bright sealing-wax red, similar to the 
deposit found in the chambers of guns, turning black on the surface on exposure to 
the air : sealed for examination. 
Experiment 75, November 1, 1873. — Experiment 20 repeated, 3800 grs. (246'286 
grms.) F. G., analysis of 20 being unsatisfactory. When exploded, cylinder perfectly 
tight ; had to put a drop of water in gas-hole before gas would come away, the hole 
being sealed by the deposit. 
Residue when got out very dark in colour ; no yellow or green apparent when put in 
bottle ; after grinding in nitrogen, a little heat appeared to be developed and a tinge of 
yellow appeared. 
s. . Crush, copper Pressure 
o. A. a. n- j • , 
cylinder. m tons. 
•5000 -1667 ' '0833 -076 10-2 
Experiment 76, November 3, 1873. — Experiment 43 repeated, results of analysis 
of previous experiment being irreconcilable; 6080 grs. (393‘986 grms.) P. 
On opening the cylinder observed that the contraction was greater than usual ; nothing 
else remarkable. 
£ . Crush, copper Pressure 
cylinder. in tons. 
•8000 -0833 -0833 -098 24-2 
Experiment 77, November 13, 1873. — Fired 6840 grs. (417*312 grms.) P. After 
firing, the cylinder was allowed to stand for 60 seconds, then tilted over to an angle of 
45° and replaced. At 75 seconds after firing it was again tilted on a different place, and 
so on up to 2 minutes. 
On opening the cylinder it was found that 
at 60 and 75 seconds after explosion the 
deposit was perfectly fluid; at 90 seconds it 
was rather thick, and at 105 seconds it hardly 
moved. 
The development of the interior surface of 
the cylinder appeared thus (see figure). 
mdccclxxv. x 
