6 REPORT—1868. 
texture or circular web. These webs are made of various diameters; and it 
is out of these webs that common rifle cartridges are made, merely by cutting 
them into the proper lengths, and enclosing them in stiff cylinders of paste- 
board, which form the cartridge. In this shape its combustion in the open 
air takes place at a speed of 10 feet per second. In these cylindrical webs 
it is also used to fill explosive shells, as it can be conveniently employed in 
this shape to pass in through the neck of the shell. Gun-cotton thread is 
spun into ropes in the usual way, up to 2 inches diameter, hollow in the 
centre. This is the form used for blasting and mining purposes; it combines 
great density with speedy explosion, and in this form it is conveniently coiled 
in casks and stowed in boxes. The gun-cotton yarn is used directly to form 
cartridges for large guns, by being wound round a bobbin, so as to form 
a spindle like that used in spinning-mills. The bobbin is a hollow tube 
of paper or wood. The object of the wooden rod is to secure in all cases the 
necessary length of chamber in the gun required for the most effective 
explosion. The gun-cotton circular web is enclosed in tubes of india-rubber 
cloth to form a match-line, in which form it is most convenient, and travels 
with speed and certainty. 
Conveyance and storage of gun-cotton.—It results from the foregoing facts 
that 1 Ib. of gun-cotton produces the effect of more than 3 Ibs. of gunpowder 
in artillery. This is a material adyantage, whether it be carried by men, by 
horses, or in waggons. It may be placed in store and preserved with great, 
safety. (L.7,&16.) The danger from explosion does not arise until it is con- 
fined, as it simply burns intensely in the open air. It may become damp, and 
even perfectly wet without injury, and may be dried by mere exposure to the 
air. This is of great value in ships of war; and in case of danger from fire, 
the magazine may be submerged without injury. 
Practical use in artillery.—It is easy to gather from the foregoing general 
facts how gun-cotton keeps the gun clean, and requires less windage, and 
therefore performs much better in continuous firing. In gunpowder there is 
68 per cent. of refuse, or the matter of fouling. In gun-cotton there is no 
residuum, and therefore no fouling. 
Experiments made by the Austrian Committee proved that 100 rounds 
could be fired with gun-cotton against 30 rounds of gunpowder. 
In firing ordnance with gun-cotton, the gun does not heat to any important 
extent. Experiments showed that 100 rounds were fired with a 6-pounder 
in 34 minutes, and the gun was raised by gun-cotton to only 122° Fahrenheit, 
whilst 100 rounds with gunpowder took 100 minutes, and raised the tem- 
perature to such a degree that water was instantly evaporated. The firing 
with the gunpowder was therefore discontinued; but the rapid firing with 
the gun-cotton was continued up to 180 rounds without any inconvenience, 
(L. 9.) The absence of fouling allows all the mechanism of a gun to have 
more exactness than where allowance is made for fouling. The absence of 
smoke promotes rapid firing and exact aim. 
The fact of smaller recoil from a gun charged with gun-cotton is established 
by direct experiment; its value is two-thirds of the recoil from gunpowder 
—the projectile effect being equal. (L. 5.) To understand this may not be 
easy. The waste of the solids of gunpowder accounts for one part of the 
saving, as in 100 Ibs. of gunpowder 68 lbs, have to be projected in addition 
to the shot, and at much higher speed. The remainder General von Lenk 
attributes to the different law of combustion; but the fact is established. 
The comparative advantage of gun-cotton and gunpowder for producing 
high velocities is shown in the following experiment with a Krupp’s cast 
