four men to lift them; and fires were
lighted, at intervals along the wall, on which were placed huge iron
vessels filled with oil and pitch.

Still the tower advanced. Its motive power could not be seen, and it
was a terrible spectacle, this enormous giant creeping silently along,
as though impelled by the breath of a demon.

From within could be distinguished the dull grating of the machinery,
and from the loopholes peered the fierce faces of the German archers as
they discharged a cloud of arrows upon the besieged.

Anselmo, the chief of the Milanese artillery, an old man, still
vigorous, with bold features and a quick eye, examined the tower
carefully, as it neared the walls. The troops, watchful of the least
movement of their leader Oberto, were ready to act; but if Anselmo's
skill did not succeed in destroying the tower, they felt that the city
would be taken.

"Let go the catapults!" cried Anselmo, his eyes always fixed upon the
machine.

The order was immediately executed, and the old man stepped back to
judge of the effect. There was a deep silence, and all gazed anxiously
upon the stern visage of their leader, as he touched the spring of the
engine. There was a violent shock and a cloud of stones dashed full
upon the front of the tower; but the hay and brushwood, with which it
was bordered, broke the force of the concussion. A second discharge was
attended with a like result.

"By my holy patron saint!" cried Anselmo, shaking his head, "the jade
is solid. If four hundred weight of stone have no more effect than a
shower of snow-balls, we have little chance of escaping Barbarossa's
companions. However, let us try again."

A larger stone was brought forward and put into the catapult; a moment
after it whistled through the air and struck heavily against the tower,
but without producing any impression.

"It is useless to try," said Anselmo; "the devil himself must have
built that tower!"

"Would it not be advisable," said Nigri, "to arrange the smaller
machines for the reception of the stormers, as we cannot prevent the
assault?"

"Let go the catapults!" interrupted Anselmo.

But it was all in vain, the advance of the machine could not be
checked; and the garrison turned their attention to the smaller
engines, which were filled with missiles of every kind, and to the
pitch and boiling oil, which was to be poured upon the enemy as he
clambered up the walls.

"Attention! hold everything in readiness