We therefore find in all the great sieges and battles of this era a large and continually increasing number of engineers and engineer troops, this force being gradually augmented as the true principles of war became better understood, and as the wants of the service required.

Even in the earliest of these battles we find the engineers taking a prominent and distinguished part.

In the war of 1688, twenty-four engineers were killed and wounded at the siege of Philipsbourg, eighteen at Namur, eight at Huy, ten at Charleroi, eight at Ath, thirty at Barcelona, &c.

Such losses were good proofs of the usefulness of these officers, and before this war was closed, their number was increased to six hundred; and in 1706 the army contained eight brigades of engineers and four companies of miners.
The engineer corps being partially disbanded in the early part of the French Revolution, great difficulty was experienced in reorganizing it and in finding competent men to supply the places of those who had been driven into exile or sacrificed during the reign of terror.

Energy and activity, combined with republican zeal, could supply the place of skill in the other arms, but the science of the engineer could not be acquired in a day.
In 1799, the staff of the engineer corps consisted of four hundred and forty-nine officers, without including the general officers, commanding departments, or those connected with the engineer troops.