one bomb can be filled before the previous one is fired.

467. A beech plug must be temporarily put in the fuze-hole of the bomb
when filled; and the men who fill cartridges and charge the bombs are
to wear flannel sleeves and magazine-shoes.

468. When ranges are desired to be obtained by reduced charges, the
measuring and filling of the cartridges must always be done in the
magazine, no matter how inconvenient it may be; and the utmost
exactness is to be observed in filling the powder-measures and
levelling off the top, as an ounce of powder makes an important
variation in the range of the bomb.

469. Extra cotton bags are to be provided to receive the reduced
charges, which are to be stowed in half barrels.

470. Every precaution that suggests itself to the officers in command
to prevent accidents, should immediately be put in force, and a
memorandum of the matter transmitted to the Ordnance Officer of the
squadron.

GENERAL RULES AND OBSERVATIONS.

471. To estimate the distance by the bursting of a bomb, where the
flash can be seen, multiply the number of seconds which elapse between
it and the sound of the report by 1,100, and the product will be
nearly the distance in feet.

472. The officer in charge of a mortar must always note the time of
flight and distance, by the above rule, for every bomb that is fired,
and likewise note when the report is not heard from the bursting
charge.

473. When going into action for a bombardment, the fore-rigging must
be come up on the side where the mortar is to be used, the
fore-topmast sent down, foresail unbent, boom and gaff laid on deck,
rigging lashed in close to the mast, head-sails to be thoroughly
wetted, spring on the cable, boats lowered from the side davits, and
all the hatches covered with tarpaulins.

474. The broadside-guns must be kept ready for action, and muskets
loaded and at hand, in case the squadron should be attacked by the
enemy's gunboats.

475. Besides bombs, various other projectiles are fired from mortars,
such as carcasses, which are shells having three holes of similar
dimensions to the fuze-hole, pierced at equal distances apart in the
upper hemisphere, with their exterior openings touching the great
circle which is perpendicular to the axis of the bore.

476. These carcasses are placed in the mortar in the same manner as
the bomb, and are filled with inflammable mixtures, and should be
transported in a vessel by themselves, as they