But to recur to the economy of the Rocket carcass; how much is not the saving of this system of bombardment enhanced, when considered with reference to naval bombardment, when the expensive construction of the large mortar vessel is viewed, together with the charge of their whole establishment, compared with the few occasions of their use, and their unfitness for general service? Whereas, by means of the Rocket, every vessel, nay, every boat, has the power of throwing carcasses without any alteration in her construction, or any impediment whatever to her general services.

So much for the comparison required as to the application of the Rocket in bombardment; I shall now proceed to the calculation of the expense of this ammunition for field service, compared with that of common artillery ammunition. In the first place, it should be stated that the Rocket will project every species of shot or shell which can be fired from field guns, and indeed, even heavier ammunition than is ordinarily used by artillery in the field. But it will be a fair criterion to make the calculation, with reference to the six and nine-pounder common ammunition; these two natures of shot or shell are projected by a small Rocket, which I have denominated the 12-pounder, and which will give horizontally, and without apparatus, the same range as that of the gun, and with apparatus, considerably more. The calculation may be stated as follows:—

£.s.d.
12-pounder Rocket{Case and stick05 6 
{Rocket composition0110½
{Labour, &c.02 0 
£0 9 4½

But this sum is capable of the following reduction, by substituting elementary force for manual labour, and by employing bamboo in lieu of the stick.

£.s.d.
[B]Reduced Price{Case and stick0 4  0 
{Composition0110½
{Driving00 6 
£0 6 4½

[B] And this is the sum that, ought to be taken in a general calculation of the advantages of which the system is capable, because to this it may be brought.

Now the cost of the shot or spherical case is the same whether projected from a gun or thrown by the Rocket; and the fixing it to the Rocket costs about the same as strapping the shot to the wooden bottom.

This 6s. 4½d. therefore is to be set against the value of the gunpowder, cartridge, &c. required for the gun, which may be estimated as follows:—

£.s.d.
6-pounder Ammn.{Charge of powder for the 6-pounder020 
{Cartridge, 3½d. wooden bottom, 2½d. and tube, 1¼d.00 7¼
£0 2 7¼
£.s.d.
9-pounder Ammn.{For the 9-pounder charge of powder030 
{Cartridge, 4½d. wooden bottom, 2½d. and tube, 1¼d.00 8¼
£0 3 8¼

Taking the average, therefore, of the six and nine-pounder ammunition, the Rocket ammunition costs 3s. 2¾d. a round more than the common ammunition.