10th. To refrain from opening fire from any series of batteries until it can be done at the same moment from all of them.
[In connection with this and other siege operations, Vauban remarks that precipitation in sieges does not hasten the close of them, but often prolongs them and renders them more bloody.]
11th. To employ the fire of the batteries and trenches, rather than open assaults, to drive the besieged from their defences, before attempting to occupy them by the besieging force.
12th. When it is decided to make an open assault, to do so by day, if there is no portion of the fire of the defences which bears upon the point to be carried that is not completely kept under by the fire of the batteries and trenches; but, in the contrary case, when the fire of the defences is not completely kept under, to make a night assault.
13th. Not to attempt an obstinate resistance to an open assault of the besieged upon any unfinished portion of the trenches; but rather to withdraw the workmen and the few troops near them to some point behind the parallel immediately in rear, and then to open a vigorous fire from it upon the assailing force.
14th. To keep within the cover of the parallel when the assailant is advancing to the assault, and leave him to expose himself to its fire as long as he pleases, and then, when he is well cut up, and has got thrown into confusion, as he necessarily will at night, in the trenches that he may have carried, to fall upon him with the bayonet and drive him out.
15th. Not to push such charges too far from the parallel, but to retire promptly, so soon as the assailant has fairly taken to flight, within the cover of the parallel, so as not to draw the fire of the besieged works.
JOURNAL OF THE ATTACK.
98. In connection with the plan of attack previously referred to (par. 78), a complete Journal of the Attack will be kept in which will be recorded day by day a detailed record of the daily progress of the siege, giving the day and hour of starting and completing each battery, parallel, approach, etc., with their daily progress, dates of opening fire from each battery, and, generally, every incident connected with the siege. This journal will be supplemented by journals kept by the chiefs of engineers and artillery, in which will be consolidated the daily reports of all subordinate commanders of these respective arms, giving the expenditure of ammunition, the performance of the guns, carriages, etc.; the modification made in details of parapets, batteries, magazines, etc., with their value; the results of trials of new devices, and special reports upon any points connected with the siege. These journals will be carefully preserved and copies transmitted to the War Department from time to time for future use.