218 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1919. 
a month. These did not, however, become actual factors in produc- 
tion. In addition to its widespread use in high-explosive shells 
T. N. T. figured both spectacularly and effectively in airplane bombs, 
some of which carried 500 pounds. 
Of phenol—also a product of the distillation of coal—the base of 
trinitrophenol or 'picric acid, our monthly production was raised 
from 670,000 pounds upon our entry into the war to 13,000,000 pounds 
a month 19 months later, and of this a considerable proportion was 
produced synthetically from benzol. 
Picric acid, which is made from phenol by treatment with nitric 
and sulphuric acids, constitutes the chief explosive used by the 
French, who found it necessary to call upon us for vast amounts, and 
in response to this demand our production rose in 12 months from 
600,000 pounds a month to 11,300,000 pounds, an increase of 2,000 
per cent. Our own Government authorized the construction of three 
picric acid plants, each of a monthly capacity of 144 million pounds. 
Only one, however, went into production before the signing of the 
armistice. 
The raw-material relation of ammonium picrate is obvious, as is 
that of tetranitroaniline, which we produced in quantity for Russia 
for the loading of boosters and fuses. Tetryl or tetranitrodimethyl- 
aniline was only used as a loading charge for boosters, but was, 
however, being turned out at the rate of 160,000 pounds a month when 
the armistice was signed. 
All this vast production of explosives was, of course, conditioned 
upon the maintenance of an adequate supply of nitric acid, which 
essential had formerly been derived from Chile in the shape of sodium 
nitrate. A gigantic program for the fixation of atmospheric nitrogen 
in various combinations was thereupon conceived and pressed into 
execution. At Sheffield, Ala., a great plant for producing ammonia 
by a modification of the Haber process was just coming into produc- 
tion at the signing of the armistice. The cyanamid process was 
installed on a grand scale at Muscle Shoals, Ala., which was starting 
production at the same time. Elsewhere the Bucher process of mak- 
ing sodium cyanide was under development. On November 11, 1918, 
-the total producing capacity of the country for ammonium nitrate 
from all sources, including Muscle Shoals and Sheffield, was 20,000,000 
pounds a month. 
Among the most notable of the great constructive operations of 
the war must be mentioned the Old Hickory plant for smokeless 
powder at Nashville, Tenn., the somewhat smaller but still vast plant 
at Nitro, and the enormous expansion of private plants, as that of the 
du Ponts at Hopewell, Va. The Old Hickory plant was self-con- 
tained and comprised nine complete powder lines, each of a capacity 
