While this deadly industry went on, the more strictly military operations were not pretermitted day nor night.  The Catholics were unwearied in watching for a chance of attack, and the Hollanders stood on the ramparts and in the trenches, straining eyes and ears through the perpetual icy mists of that black winter to catch the sight and sound of a coming foe.  Especially the by-watches, as they were called, were enough to break down constitutions of iron; for, all day and night, men were stationed in the inundated regions, bound on pain of death to stand in the water and watch for a possible movement of the enemy, until the waves should rise so high as to make it necessary to swim.  Then, until the tide fell again, there was brief repose.

And so the dreary winter faded away at last into chill and blustering spring.  On the 13th of April a hurricane, such as had not occurred since the siege began; raged across the ocean, deluging and shattering the devoted town.  The waters rose over dyke and parapet, and the wind swept from the streets and ramparts every living thing.  Not a soldier or sailor could keep his feet, the chief tower of the church was blown into the square, chimneys and windows crashed on all sides, and the elements had their holiday, as if to prove how helpless a thing was man, however fierce and determined, when the powers of Nature arose in their strength.  It was as if no siege existed, as if no hostile armies had been lying nearly two years long close to each other, and losing no opportunity to fly at each other’s throats.  The strife of wind and ocean gave a respite to human rage.

It was but a brief respite.  At nightfall there was a lull in the tempest, and the garrison crept again to the ramparts.  Instantly the departing roar of the winds and waters were succeeded by fainter but still more threatening sounds, and the sentinels and the drums and trumpets to rally the garrison, when the attack came.  The sleepless Spaniards were already upon them.  In the Porcupine fort, a blaze of wickerwork and building materials suddenly illuminated the gathering gloom of night; and the loud cries of the assailants, who had succeeded in kindling this fire by their missiles, proclaimed the fierceness of the attack.  Governor Dorp was himself in the fort, straining every nerve to extinguish the flames, and to hold this most important position.  He was successful.  After a brief but bloody encounter the Spaniards were repulsed with heavy loss.  All was quiet again, and the garrison in the Porcupine were congratulating themselves on their victory when suddenly the ubiquitous Philip Fleeting plunged, with a face of horror, into the governor’s quarters, informing him that the attack on the redoubt had been a feint, and that the Spaniards were at that very moment swarming all over the three external forts, called the South Square, the West Square, and the Polder.  These points, which have been already described, were most essential to the protection of the place, as without them the whole counterscarp was in danger.  It was to save those exposed but vital positions that Sir Francis Vere had resorted to the slippery device of the last Christmas Eve but one.