Zuyder Zee was only separated from the Harlem mere by a slender thread of land. Over this ran the causeway between the two sister cities, now so unfortunately in arms against each other. Midway between the two, the dyke was pierced and closed again with a system of sluice-works, which when opened admitted the waters of the lake into those of the estuary, and caused an inundation of the surrounding country. The city was one of the largest and most beautiful in the Netherlands. It was also one of the weakest.--The walls were of antique construction, turreted, but not strong. The extent and feebleness of the defences made a large garrison necessary, but unfortunately, the garrison was even weaker than the walls. The city's main reliance was on the stout hearts of the inhabitants. The streets were, for that day, spacious and regular; the canals planted with limes and poplars. The ancient church of Saint Bavon, a large imposing structure of brick, stood almost in the centre of the place, the most prominent object, not only of the town but of the province, visible over leagues of sea and of land more level than the sea, and seeming to gather the whole quiet little city under its sacred and protective wings. Its tall open-work leaden spire was surmounted by a colossal crown, which an exalted imagination might have regarded as the emblematic guerdon of martyrdom held aloft over the city, to reward its heroism and its agony. It was at once obvious that the watery expanse between Harlem and Amsterdam would be the principal theatre of the operations about to commence. The siege was soon begun. The fugitive burgomaster, De Fries, had tho effrontery, with the advice of Alva, to address a letter to the citizens, urging them to surrender at discretion. The messenger was hanged--a cruel but practical answer, which put an end to all further traitorous communications. This was in the first week of December. On the 10th, Don Frederic, sent a strong detachment to capture the fort and village of Sparendam, as an indispensable preliminary to the commencement of the siege. A peasant having shown Zapata, the commander of the expedition, a secret passage across the flooded and frozen meadows, the Spaniards stormed the place gallantly, routed the whole garrison, killed three hundred, and took possession of the works and village. Next day, Don Frederic appeared before the walls of Harlem, and proceeded regularly to invest the place. The misty weather favored his operations, nor did he cease reinforcing himself; until at least thirty thousand men, including fifteen hundred cavalry, had been encamped around the city. The Germans, under Count Overstein, were stationed in a beautiful and extensive grove of limes and beeches, which spread between the southern walls and the shore of Harlem Lake. Don Frederic, with his Spaniards, took up a position on the opposite side, at a place called the House of Kleef, the ruins of which still remain.