67. Precautions against Dampness in Magazines for Siege Batteries.—Underground magazines of the character above described are, of necessity, sometimes damp. The only ventilation usually possible is obtained by leaving the door open, the air being changed more or less by the men going in and out.
The passage leading to the powder-chamber should enter it at the middle, and in the service of the guns one half of the chamber should be emptied on one day and the other half on the next. This will usually limit the time which a cartridge is exposed to the dampness of the magazine to a maximum of one or two days.
CHAPTER V.
SIEGE OPERATIONS.
THE ATTACK.
68. Siege operations include all the steps taken from the first approach to the work up to its final capture. These taken in regular order are as stated in Chapter II: the investment, the distant artillery attack, the construction of approaches and parallels, breaching by artillery or mines, and the final assault.
For convenience in description the siege has been divided into three periods. The first period includes the preliminary operations up to the completion of the investment.
The second period includes all the operations between breaking ground for the batteries of the first artillery position and the first parallel, up to the completion of the most advanced parallel and the occupation of a position near the foot of the glacis from which the attack is to be made upon the breach, either by assault or sap.
The third period comprises the advance from the last parallel, and all subsequent operations up to the capture of the last entrenchment and the surrender of the garrison.
The first and second periods are sometimes known as the “distant” and the third period as the “close attack.”