So much misapprehension having been entertained with regard to the expense of the Rocket system, it is very important, for the true understanding of the weapon, to prove, that it is by far the cheapest mode of applying artillery ammunition, both in bombardment and in the field.
To begin with the expense of making the 32-pounder Rocket Carcass, which has hitherto been principally used in bombardments, compared with the 10-inch Carcass, which conveys even less combustible matter.
| £. | s. | d. | ||
| Cost of a 32-pounder Rocket Carcass, complete for firing in the present mode of manufacture. | {Case | 0 | 5 | 0 |
| {Cone | 0 | 2 | 11 | |
| {Stick | 0 | 2 | 6 | |
| {Rocket composition | 0 | 3 | 9 | |
| {Carcass ditto | 0 | 2 | 3 | |
| {Labour, paint, &c. | 0 | 5 | 6 | |
| £1 | 1 | 11 |
If the construction were more systematic, and elementary force used instead of manual labour, the expense of driving the Rocket might be reduced four-fifths, which would lower the amount to about 18s. each Rocket, complete; and if bamboo were substituted, which I am endeavouring to accomplish, for the stick, the whole expense of each 32-pounder Carcass Rocket would be about 16s. each.
Now as the calculation of the expense of the Rocket includes that of the projectile force, which conveys it 3,000 yards; to equalize the comparison, to the cost of the spherical carcass must be added that of the charge of powder required to convey it the same distance.
| £. | s. | d. | ||
| Cost of a 10-inch Spherical Carcass, with a proportionate charge of powder, &c. | {Value of a 10-inch spherical carcass | 0 | 15 | 7 |
| {Ditto of charge of powder, to range it 3,000 yards | 0 | 6 | 0 | |
| {Cartridge tube, &c. | 0 | 1 | 0 | |
| £l | 2 | 7 |
So that even with the present disadvantages of manufacture, there is an actual saving in the 32-pounder Rocket carcass itself, which contains more composition than the 10-inch spherical carcass, without allowing any thing for the difference of expense of the Rocket apparatus, and that of the mortar, mortar beds, platforms, &c. which, together with the difficulty of transport, constitute the greatest expense of throwing the common carcass; whereas, the cost of apparatus for the use of the Rocket carcass does not originally exceed £5; and indeed, on most occasions, the Rocket may, as has been shewn, be thrown even without any apparatus at all: besides which, it may be stated, that a transport of 250 tons will convey 5,000 Rocket carcasses, with every thing required for using them, on a very extensive scale; while on shore, a common ammunition waggon will carry 60 rounds, with the requisites for action. The difference in all these respects, as to the 10-inch spherical carcass, its mortars, &c. is too striking to need specifying.
But the comparison as to expense is still more in favour of the Rocket, when compared with the larger natures of carcasses. The 13-inch spherical carcass costs £1. 17s. 11½d. to throw it 2,500 yards; the 32-pounder Rocket carcass, conveying the same quantity of combustible matter, does not cost more than £1. 5s. 0d.—so that in this case there is a saving on the first cost of 12s. 11½d. Now the large Rocket carcass requires no more apparatus than the small one, and the difference of weight, as to carriage, is little more than that of the different quantities of combustible matter contained in each, while the difference of weight of the 13-inch and 10-inch carcasses is at least double, as is also that of the mortars; and, consequently, all the other comparative charges are enhanced in the same proportion.
In like manner, the 42-pounder Carcass Rocket, which contains from 15 to 18 lbs. of combustible matter, will be found considerably cheaper in the first cost than the 13-inch spherical carcass: and a proportionate economy, including the ratio of increased effect, will attach also to the still larger natures of Rockets which I have now made. Thus the first cost of the 6-inch Rocket, weighing 150 lbs. and containing 40 lbs. of combustible matter, is not more than £3. 10s. that is to say, less than double the first cost of the 13-inch spherical carcass, though its conflagrating powers, or the quantity of combustible matter conveyed by it, are three times as great, and its mass and penetration are half as much again as that of the 10-inch shell or carcass. It is evident, therefore, that however extended the magnitude of Rockets may be, and I am now endeavouring to construct some, the falling mass of which will be considerably more than that of the 13-inch shell or carcass, and whose powers, therefore, either of explosion or conflagration, will rise even in a higher ratio, still, although the first cost may exceed that of any projectile at present thrown, on a comparison of effects, there will be a great saving in favour of the Rocket System.
It is difficult to make a precise calculation as to the average expense of every common shell or carcass, actually thrown against the enemy; but it is generally supposed and admitted, that, on a moderate estimate, these missiles, one with another, cannot cost government less than £5 each; nor can this be doubted, when, in addition to the first cost of the ammunition, that of the ordnance, and the charges incidental to its application, are considered. But as to the Rocket and its apparatus, it has been seen, that the principal expense is that of the first construction, an expense, which it must be fairly stated, that the charges of conveyance cannot more than double under any circumstances; so that where the mode of throwing carcasses by 32-pounder Rockets is adopted, there is, at least, an average saving of £3 on every carcass so thrown, and proportionally for the larger natures; especially as not only the conflagrating powers of the spherical carcass are equalled even by the 32-pounder Rocket, but greatly exceeded by the larger Rockets; and the more especially indeed, as the difference of accuracy, for the purposes of bombardment, is not worthy to be mentioned, since it is no uncommon thing for shells fired from a mortar at long ranges, to spread to the right and left of each other, upwards of 500 or even 600 yards, as was lately proved by a series of experiments, where the mortar bed was actually fixed in the ground; an aberration which the Rocket will never equal, unless some accident happens to the stick in firing; and this, I may venture to say, does not occur oftener than the failure of the fuze in the firing of shells. The fact is, that whatever aberration does exist in the Rocket, it is distinctly seen; whereas, in ordinary projectiles it is scarcely to be traced—and hence has arisen a very exaggerated notion of the inaccuracy of the former.