The latter plan has sometimes been adopted when the works of the place were weak and improperly defended; where the time and means were wanting for conducting a regular siege; or where the assailants were ignorant of the means proper to be resorted to for the reduction of the fortress.

Such operations, however, are usually attended by an immense sacrifice of human life, and the general who neglects to employ all the resources of the engineer's art in carrying on a siege, is justly chargeable with the lives of his men.

In the siege of Cambrai, Louis XIV., on the solicitation of Du Metz, but contrary to the advice of Vauban, ordered the demi-lune to be taken by assault, instead of waiting for the result of a regular siege.

The assault was made, but it was unsuccessful, and the French sustained great losses.

The king now directed Vauban to take the demi-lune by regular approaches, which was done in a very short time, and with a loss of _only five men!_ Again, at the siege of Ypres, the generals advised an assault before the breaches were ready.