_First period_ of the siege; 5 rounds per gun, per day, with only half the full charge, or one-sixth the weight of the shot, and for only such guns as can act. _Second period_; 20 rounds per gun, per day, with one-sixth the weight of the shot. _Third-period_; 60 rounds per gun, per day, with the full charge, or one-third the weight of the shot. _Mortars_; at 20 shells per day, from the first opening of the trenches to the capitulation. _Stone Mortars_; 80 rounds per mortar, for every 24 hours, from the establishment of the demi-parallels to the capitulation; about 13 days. _Light_, and _Fire balls_; five every night, for each mortar, from the opening of the trenches to the eighth day, and three from that time to the end of the siege. These amount to about 700 for guns. 400 for mortars. 1000 for stone do. This proportion and arrangement is however made upon a supposition, that the place has no countermines to retard the progress of the besiegers, to a period beyond what is abovementioned; but the same author estimates, that a similar place, with the covert way properly countermined beforehand, and those countermines properly disputed, may retard a siege at least 2 months; and that if the other works be likewise effectually countermined and defended, the siege may be still prolonged another month. The above proportion is therefore to be further regulated, as the strength of the place is increased by these or any other means. These considerations should likewise be attended to, in the formation of an estimate of ammunition and stores for the siege of a fortified place. See _Carriage_, _Platform_, _Park_, and the different kinds of artillery, as _Gun_, _Mortar_, _Howitzer_, &c. The ammunition for small arms is estimated by this author as follows: ¹⁄₄ of a pound of gunpowder, or 10 rounds per day, per man, for all the ordinary guards. 1¹⁄₄ lbs. or 50 rounds per man, per 12 hours, for all extraordinary guards. ⁵⁄₈ of a pound, or 25 rounds for every man on picket, during the period of his duty. ARTILLERY, in a military acceptation of the term, signifies every species of light or heavy ordnance. It is classed under specific heads; the most important of which are-- _Field_ ARTILLERY, which includes every requisite to forward the operations of an army, or of any part of an army acting offensively or defensively in the field. Field artillery may be divided into two distinct classes--_Field Artillery_, commonly called the _Park_, and _Horse Artillery_.