Explanation of the above drawing of an apperratus for Blowing up Enemys Ships, when attempting to Enter our harbours with an hostile Intention, to wit, AAA. keggs of powder too thirds full, with a weight at one side to keep that side down, so that the Emty part of the keggs lies uppermost, which keggs must be made water tight. B.B a Rope that holds them together, c.c.c. gun locks, placed within the keggs above the gunpowder fastened to the side of a Crosspiece1 for that purpose, D.D.D. Brass or Copper Rods which Enter through the heads of the keggs, Corked tight, so as to be waterproof, the inner end fastened to the triggers by a Sink, E.E.E. the above metioned weight to keep the keggs Ballasted, F.F.F. Ropes fastened to the keggs underside; the Lower end to the Anchors or Aney other weight that will not Easily dragg, which Ropes or Cords are only to be of strenght suffitient to hold the kegg stationary a Lietle underwater, but to Brake by the ships Running against the Rope that Conects the keggs, H.H.H. Ropes fastened to the outer end of the Brass Rods, sufitiently long to lie in a Coil at the Bottom of the Channel, the lower end fastened to the Rings of the Anchors, I.I.I.–K.K. Small Bouys with a hole through them so that they2 may slide on the Couppeling rope, and keep the same from sinking, L. the vessels stern, Running against the Rope. B.B. snapping the Ropes F.F.F. and driving the Rope B.B. with its keggs ahead, by which the Ropes HHH become taut3 and draw the triggers of the locks, by means of the Brass rods and if the locks are good will Cause an Explotion, Note the keggs must be no more distance apart then about 150 feet so that if the Channel is wide a greater number will be required, for If [they] are too far apart they4 will swing behind the Ship Insted under it this apperatus may be kep Redy and nead not be Laid till the Enemy is in sight or Immediatly Expected, and if not wanted may be taken up again, by untying the ropes from the Brass rods, a gard bote ought be kep at the place, to warn freindly vessels, till the apperratus is out of the way,