"You will gain a day by the assault," said Vauban, "but you will lose a thousand men." The king directed the regular works to be continued, and the next day the place was taken with but little loss to the besiegers.
But a work may be of such a character as to render it unnecessary to resort to all the works of attack which would be required for the reduction of a regular bastioned fort, on a horizontal site.

For example: the nature of the ground may be such as to enable the troops to approach to the foot of the glacis, without erecting any works whatever; of course, all the works up to the third parallel may in this case be dispensed with without any violation of the rules of a siege.

Again, the point of attack may be such that the other parts of the place will not flank the works of approach; here a single line of _boyaux_ and short parallels may be all-sufficient.
But for the purpose of discussion, we will here suppose the place besieged to be a regular bastioned work on a horizontal site, (Fig.
54.) The operations of the siege may be divided into three distinct periods.
1st.

The preliminary operations of the attack and defence previous to the opening of the trenches.
2d.

The operations of the two parties from the opening of the trenches to the establishment of the third parallel.
3d.