ROCKET SHELLS, AND ARTILLERY OE THE EUTTJRE. 
295 
therefore probably be too thick to be inserted in the ordinary way, 
and it would occupy too much internal space if wholly inside with a 
hollow cylinder screwed over it; hence a smaller fuze (perhaps of metal) 
must be used, which will be blown out on ignition of the rocket com¬ 
position. (See figure.) 
Now suppose shells without head-vents are alone to be employed; 
then some fuze like the Armstrong A time must be used. The solid 
plug closing the head of the shell might form also the head of the fuze 
(as in figure). 
Thirdly, suppose it is advisable to fire on both plans; then the last 
fuze would be used in the one case, and in the other the same fuze 
with a hollow cylindrical head, through which certain parts of the fuze 
would be blown, on ignition of the rocket, and afterwards it would act 
as a vent. (See figure.) 
The same embarrassment does not, however, occur with the percussion 
fuze ; the momentum of the rocket shell being equal to that of the 
ordinary projectile, a fuze on the plan of the “B.L. plain percussion” 
will probably be' found to answer very well, with a hollow or solid plug* 
screwed over it. With the head-vent, some portions of the fuze must 
be made so that the ignition of the shell will blow them out. 
To complete the shell, I would propose to have a layer of gun-cotton 
(in suitable form) between the rocket composition and the walls of the 
shell; or, if that, is not possible, the gun-cotton might be arranged in 
grooves in the metal of the shell, which would also facilitate the break¬ 
ing up of the shelf on explosion. 
This development of my idea is necessarily very defective, and 
artillerists of practical experience in the construction of ammunition 
will no doubt be able to make many material changes for the better, 
should the principle of rocket shells be considered worth a trial. 
In fine, a word on the action and application of the proposed shell. 
The rocket .shell being fired with service charge from a rifled gun, 
proceeds with all the accuracy of the ordinary projectile until the fuze 
ignites the composition. Gas will now be rapidly generated, and the 
internal pressure will increase until the base plugs, acting upon the base 
plate, force it off. Our rocket shell will now proceed with accelerated 
velocity (supposing no head-vent) and with volumes of fire issuing from 
its base. It. will resemble the ordinary war rocket, but with these 
differences: that instead of soaring up into the air and coming down 
at a very high angle, with low velocity and small momentum, a flat 
trajectory will carry it near the groundj and there will be no loss of 
momentum or variation in the position of the centre of gravity from the 
burning of the composition till the shell comes within its sphere of 
action. 
To ensure all the moral effects of the shell, it should be ignited some 
200 or 400 yds. in front of the enemy’s line by means of a time fuze. 
Against solid buildings to be fired and destroyed, a percussion fuze will 
be found more useful. 
When employing the head-vent, more flame will be generated before 
the base-vents are opened, the flame will escape more rapidly, and the 
