2. The booms must be wetted by the pumps before the tarpaulins and mortar-hatches are taken off; and a wooden skreen, 5 feet square, is to be hung under the booms, over each mortar, to receive the fire from the vents. 3. The embrasures being fixed and properly secured, the port must be let down low enough to be covered by the sole of the embrasure. Previous to its being let down, a spar must be lashed across it, to which the tackles for raising it again must be fixed; this spar serves to project the tackles clear of the explosion. 4. The mortars must not be fired through the embrasures at a lower angle than 20 degrees, nor with a greater charge than 5 lbs. of powder. 5. Previous to firing, the doors of the bulkhead, under the quarter-deck, must be shut, to prevent the cabin being injured by the explosion. 6. The bed must be wedged in the circular curb, as soon as the mortar is pointed, to prevent re-action; the first wedge being driven tight, before the rear ones are fixed, in order to give the full bearing on the table, as well as the rear of the bed. The holes for dog-bolts must be corked up, to prevent the sparks falling into them. 7. When any shells are to be used on board the bomb, they must be fixed on board the tender, and brought from thence in boxes in her long-boat; and kept along side the bomb-ship till wanted, carefully covered up. 8. In the old constructed bomb-vessels it was necessary to hoist out the booms, and raft them along side previous to firing; but in these new ones, with embrasures, only the boats need be hoisted out; after which the mortars may be prepared for action in 10 minutes. _Proportion of Ordnance and Ammunition for a Bomb Ship, carrying two 10 inch Mortars, to fire at low angles, and at 45 degrees, four 68 Prs. and six 18 Prs. Carronades._