EXPLOSIVES—0’HERN, 257 
powder. While there has been insufficient time since the adoption of 
this stabilizer to fully determine its advantages under ordinary con- 
ditions of storage, tests made at elevated temperatures have indicated 
that its presence will probably double the life of the powder. That 
the life of the smokeless powders manufactured for the United States 
service, even without the stabilizer, has been very satisfactory is 
evident from the fact that there is powder 14 years old now on hand 
in fairly satisfactory condition. There is a possibility that in de- 
teriorating, the chemical action may become so violent as to cause 
spontaneous ignition of the powder or of the gas being developed. 
The Army and Navy in this country have been practically free from 
this source of trouble, but there have been a number of disastrous 
explosions from this cause abroad. Within the past few years the 
French have lost two battleships from this cause, the Brazilians one, 
and the Japanese one. In order to guard against such a possible source 
of danger, samples of all lots of powder are kept under constant 
observation at the powder factories and at storage magazines. Any 
serious change taking place is thus promptly detected and the corre- 
sponding lot of powder withdrawn from service. 
Source of supply.—The smokeless powder needed by the United 
States Army and Navy is in part manufactured in Government plants 
and in part purchased from private manufacturers. The smokeless 
powder is made at all the plants, both Government and private, in 
accordance with specifications prepared by a joint board of Army 
and Navy officers, thus insuring a uniform and satisfactory product. 
The specifications permit the use of only the highest grade materials 
and prescribe such tests at the various stages of manufacture as ‘to 
insure a high-grade product. The most important details of manu- 
facture as prescribed by the specifications have been given in the 
discussion of the manufacture of nitrocellulose. 
Tests.—The usual tests for chemical stability are made at elevated 
temperatures in order to bring their completion within a reasonable 
time limit. One of these is made with the powder at 135° C., the 
requirement being that the gases developed by the decomposition 
must not turn litmus paper to a standard red in less than 1 hour and 
45 minutes, nor must any sample explode in less than 5 hours. 
Another test is made at 115° C., the requirement being that the loss 
in weight must not exceed a prescribed limit as a result of exposure 
to this temperature for 8 hours per day for six days. A third test 
is made at 65.5° C., the requirement being that no nitrous fumes 
shall be developed in less than a prescribed number of days, dependent 
upon the size of the grain being tested. To guard against brittleness, 
which might result in the grain being split or shattered while burning, 
73176°—-sm 1914——_117 
