Observations on these inventions

It having been fully proved that the explosion of a Submarine Bomb under a vessel will completely destroy her, it is now necessary to consider the expence of the two kinds of Bombs and their application; The expence of the Bomb complete, with the instantanious lock will be as follows

£SD
Lock200
Bomb of Copper2100
100 lb of powder7100
Anchor or weight and lines200
£ 1400
The Bomb with the clockwork Lock
Lock1000
Bomb of Copper2100
100 lb of powder7100
Cork and lines200
£ 2200

The Average price is 18 £ and each bomb of 18 £ Value is of a power to do as much execution as a fire ship which costs 2 or 3 thousand; 6,660 of them may be made for 120 thousand pounds or the first cost of one first rate Ship of the line when engines of such destructive powers can be multiplied to so great a degree, and at an expence which cannot be felt by an opulent nation the practice of them may produce novel and serious consequences.

PLATE THE NINTH

In cases where a nation commands the seas as in the present state of the British marine, the Seamen can approach sufficiently near the Enemy’s harbours and roadsteads to use such engines from common boats; by which means several hundred Bombs with instantanious Locks might be anchored in the passages leading to the Texel, Havre, Brest or other ports of the Enemy which would render it impossible for any Vessel to move in or out. But it may be said that the Enemy are already completely blockaded and England has no need for such a mode of war; this I admit, but this mode is less expensive than the Usual method of Blockading and destressing an Enemy’s commerce; yet should the economy not be thought of importance Still this invention has to be considered in another point of View, and that of the most interesting kind, Which is;

how would it affect the commerce and marine of England had the French the means of anchoring 20 or 20 thousand such Bombs in the channels to the Thames in the Bays, Harbours, Roadsteads, and a long the coast of England, scotland or Ireland;

I will now endavour to Shew what an Economic simple and certain means this would give to France to totally destroy the British Marine