MODERN GUNPOWDER AND CORDITE. 
281 
1st. Gun-cotton. —Trinitro-cellulose, C 6 H 7 0 2 3(N0 3 ), obtained by tlie action 
of nitric acid upon cotton, viz. :•—■ 
C 6 H 7 0 2 3(H0) + 3(HN0 3 )=CgH 7 0 2 3(N03)+ 3H 2 0. 
Cotton or Cellulose. Nitric acid. Gun-cotton. Water. 
2nd. Nitro-glycerin— C 3 H 5 3(N0 3 ) obtained by tlie action of nitric acid on 
glycerin. 
3rd Picric Jcid. —Trinitroplienole, C 6 H 3 3(N0 2 )0, formed by boiling “ car¬ 
bolic acid ” or plienole with fuming nitric acid. 
These may be taken as the parents of the majority of the smokeless 
powders which are deserving of consideration. 
As most of us are acquainted with the manufacture of gun-cotton, 
and we need not follow up that of picric acid, I propose to only give a 
sketch of the processes of manufacture of nitro-glycerine now being 
made in tons weekly at W altham Abbey. 
Before describing the processes I may as well tell you that it has 
been confidently stated, by a recent contributor to the daily press, that 
any tyu’o can make nitro-glycerine. This may possibly be the case; 
but if much nitro-glycerine be required, a large stock of tyros should 
be kept in hand to replace those who would undoubtedly be expended ! 
The manufacturing processes are exhibited on the diagram before you, 
and we may observe that in the preliminary operations the temperature 
must not be permitted to rise above a certain point, about 70*5° Fahr., 
and later on it must not be allowed to fall below a certain point, 50° 
Fahr. We have here the diagram (PI. II) intended to show the construc¬ 
tion and general arrangement of a nitro-glycerine factory. It is well to 
note that the various danger houses appear to be close together as shown 
in the diagram, whereas in reality they are hundreds of feet apart; and 
it would require paper of very inconvenient length to represent, in a 
satisfactory manner, the lateral extent of the various buildings. 
The danger houses are separated not only by distance, but by heavy 
traverses, like walls of a fort, which isolate the buildings, and it is hoped 
that if an explosion took place, these traverses would confine the ex¬ 
plosion to the exact locality where it occurs. The houses are lightly 
constructed of wood, and the traverses are very heavy solid masonry. 
The manufacture of nitro-glycerine is carried out as follows :— 
The acids employed (nitric or sulphuric) are mixed, in a raised tank, 
in the acid store (Plate II) in the proportions of nitric acid 992 lbs., 
sulphuric acid 1680 lbs. The mixed acids are then allowed to run off 
into cooling or store tanks, where they remain until they lose the heat 
which has been generated by mixing. 
The mixed acids, when ready for use, are passed into what is called 
the “egg.” This is an iron vessel, egg-shaped at the bottom, and is 
an ingenious contrivance for dispensing with the use of pumps, the 
valves of which would be almost immediately destroyed by the corro¬ 
sive action of the acids. 
When the charge is ready to be transferred to the tank, A, in the 
charge house (vide Plate II), air is driven into the “egg” from an air 
engine, and the pressure of air on the surface of the acids forces them 
Nitro- 
Glycerin. 
