If the besieging force is of numerical strength enough (after leaving a corps before the place four times the amount of the garrison) to cope with the relieving army, it may remove more than one day’s march from the place; but if it be inferior in numbers after providing for the siege, as above stated, it should remain only a short day’s march from the spot, in order to fall back upon its lines, if necessary, or receive succor in case of attack.
If the investing corps and army of observation are only equal when united to the relieving force, the besieging army should remain entire within, or near its lines, and push the works and the siege with the greatest activity.
NOTE.
“When we undertake a siege,” says Montécuculli, “we should not seek to place ourselves opposite the weakest part of the fortress, but at the point most favorable for establishing a camp and executing the designs we have in view.”
This maxim was well understood by the Duke of Berwick. Sent to form the siege of Nice in 1706, he determined to attack on the side of Montalban, contrary to the advice of Vauban, and even to the orders of the king. Having a very small army at his disposal, he began by securing his camp. This he did by constructing redoubts upon the heights that shut in the space between the Var and the Paillon, two rivers which supported his flanks. By this means, he protected himself against a surprise; for the Duke of Savoy, having the power of debouching suddenly by the Col de Tende, it was necessary that the marshal should be enabled to assemble his forces, so as to move rapidly upon his adversary, and fight him before he got into position; otherwise his inferiority in numbers would have obliged him to raise the siege.