be seen that the town was blotted out, and that on the site of the Cité was built this stern fortified camp, which was a charge upon the people to keep in repair, and to be always ready for the use of the Roman Legions. After generations, when the surrounding country had become tranquil, the Roman Camp became a Roman Colony, enjoying peace and prosperity for three centuries.

In 359 A. D. the Roman Emperor Julian found it again necessary to fortify the place against the Germans, and the formal fortress entered another stage of its existence as a Gallo-Roman Cité. (Figure 4.)

Julian had then about him Byzantine engineers, the most skilled in the world in fortifying places. They began by removing the houses that had been built on the slopes of the plateau in times of peace, thus restoring all the military ad

vantage of the slope, as in the Roman Camp. The ramparts were of wellfounded masonry with stone towers. The northern exposed front was made longer, with a fosse and palisades, and a vallum and outwork, (A.) The gates, tête de pont, &c., were protected by strong towers, and the Cité thus fortified (Figure 5) was able to defy the barbarians, who did not know how to undertake the siege of a well-defended place.

In the twelfth century the fortress had become a feudal castle, (Figure 6,) and in 1180 the Baron decided to greatly strengthen its defenses. He sent for a master of the works-a native of Troyes, whom he had known in Palestine-and together they devised the stronghold shown in Figure 7.

This great increase in the strength of the Castle aroused the jealousy of the Baron's over-lord, the Duke of Burgundy,

who seized upon a pretext for a quarrel, and moved to attack the Castle with his army. The Baron prepared for defense, but sent a secret message for help to King Philip Augustus of France. The siege that followed used all the resources of that most picturesque age of warfare, and it is interesting to record as the last test of the fortress before the use of gunpowder.

The Baron had on could not hope to

nd!

teau, but only the castle. This the Duke completely invested, closing the bridges and building an intrenchment or contravallation across the plateau north of the castle. On each end of this contravallation the besiegers built a wooden tower. The Baron, who had brought the secret of Greek fire from the East, promptly destroyed one of these towers in the night by hurling Greek fire from his largest trebuchet, following this with a

ie of the garrison, which inflicted

evidence.

But it also must be remem

bered that the first artillery imitated the trebouchet of the mediaeval siege, and for attack and defense there was not yet any change in methods brought about by the new weapon.

The masonry walls were much more massive, and, as will be seen in the plan, new strong towers had been built projecting from the walls. These were devised with great pains and misdirected ingenuity to contain the new artillery. Clumsy as were the resultant works, these artillery towers were the ancestors of the bastion.

In a month's siege, sustained by the fortress at this stage by the army of Louis XI. of France, (1478,) the artillery of both parties is thus described:

FIG. 6-THE FEUDAL CASTLE

great loss in the confusion caused by the fire.

The besiegers retaliated by bringing up trebouchets and mangonels, which forced the garrison to give up the barbican. The besiegers then brought up a cat, a movable wooden gallery, under which they mined the wall and battered it down with a bossom, gaining the outer court after days of bloody fighting.

The besieged had destroyed a huge new movable tower with their Greek fire -thus giving the old fortress revenge for the Roman movable tower which had captured it over 1,200 years before-and the garrison was still holding out manfully after more than forty days of siege, when the place was relieved by the approach of the French King's army.

The Coming of Gunpowder

In the next 200 years the fortress had been compelled to face new conditions. (Figure 8.) A new force had appeared, and the first awkward attempts to defend against artillery with artillery were in

this siege was almost a repetition of the siege of the feudal castle, with these primitive cannon taking the place of the stone-throwing machines.

These cannon threw large stones, some of them of 200 pounds weight, and, though they caused greater losses to the besiegers, they also were more destructive to masonry defenses at close quarters, and they made it easier to undermine the walls. The northern outwork, the boulevard at D in the plan, was first reduced, then the tower and northern rampart at E were battered in, and the last refuge of the garrison at A was surrendered twenty-seven days after the first investment.

Artillery and the Bastion

In the seventeenth century engineers were beginning to learn the use of the new artillery arm. It became evident that, against this more powerful machine, the weakness of a formal fortress lay in allowing the enemy to get near

FIG. 9 THE BASTIONS OF BAR-LE-DUC

enough to breach the walls. The next phase of the fortress, (Figure 9,) designed by Bar-le-Duc in the reign of Henry IV., marked the appearance of the bastion instead of the artillery tower, which greatly increased the area of defensive artillery. On the north the boulevard and towers had been replaced by bastions, and by this means the enemy was forced to begin operations at 1,000 yards. It is hard to realize that in those days 1,000 yards was not an effective range for artillery.

In 1636 these defenses successfully resisted an attempt to besiege them by the Imperialist troops, using trench approaches, which afterward became so highly developed in siege warfare. But the fortress was well commanded, and the attacking army, badly led and illdisciplined, was ordered to raise the siege after four weeks of useless effort.

The next stage of the fortress (Figure 10) shows the highest development of the bastion by the great French en