CAPTAIN NOBLE AND MR. E. A. ABEL ON FIRED GUNPOWDER. 
155 
appeared to proceed. On taking the crucibles from the furnace, the height of the con- 
tents (which left marks on the crucibles) was noted, and the volume of the deposit and 
the amount of contraction were measured by means of mercury, with the following 
results : — 
Powder-residue. 
Volume at 1700° C. =17-859 cub. centims. 
Volume at 0°C. =10-044 „ 
Expansion between 0° and 1700°=7’815 cub. centims., =77*8 per cent. 
Potassium carbonate and liver of sulphur. 
Volume at 1700° C. =28-188 cub. centims. 
Volume at 0°C. =14-580 „ 
13-608 „ 
.-. expansion between 0°C. and 1700° C. =13-608, =93-3 per cent. 
With the above two crucibles there was also a third, containing powder-residue, and 
in this crucible a piece of platinum was placed. The expansion measured was over 100 
per cent., but could not be depended on, on account of the platinum. The metal was 
not appreciably altered by the heat. 
Experiment 83.— Experiment 79 repeated. 
Experiment 84. — Fired 5320 grs. (344-74 grms.) F. G. in small cylinder. Put a piece 
of platinum wire 4 inches long (100 millims.), 16 W. G. (1-5 millim. in diameter), with 
the powder. This wire showed signs of fusion on the surface, but was not at all melted. 
Experiment 85, February 18, 1874. — Fired 5320 grs. (344-736 grms.) E. L. G. in 
cylinder. Placed in cylinder a piece of platinum wire 4 inches (100 millims.) long and 
0-04 inch (1 millim.) in diameter. The wire was superficially fused, but otherwise little 
altered. No crusher used, the gauge having been destroyed in experiment 83. 
Experiment 86, February 19, 1874.— Fired 5320 grs. (344-736 grms.) E. L. G. in 
same cylinder. Placed in the cylinder a piece of platinum wire of same dimensions as 
in last experiment, also the same length of copper wire, 0-13 inch(3-2 millims.)in diameter. 
The copper was completely fused and firmly attached to the cylinder, it being found 
necessary to remove it with a chisel. The platinum wire was superficially fused, as in 
the last experiment. 
