During the days when the prosperity of the United Provinces was at its height,--that is, during the latter half of the 17th century,--it could hardly be perceived that any one district of Amsterdam was busier than another, at any one hour of the day. There was traffic in the markets, traffic on the quays, the pursuit of traffic in the streets, and preparation for traffic in the houses. Even at night, when the casks which had been piled before the doors were all rolled under shelter, and dogs were left to watch the bales of merchandize which could not be stowed away before dark, there was, to the eye of a stranger, little of what he had been accustomed to consider as repose. Lights glanced on the tossing surface of the Amstel, as homeward-bound vessels made for the harbour, or departing ships took advantage of the tide to get under weigh. The hail of the pilots or the quay-keepers, or of a careful watchman here and there, or the growl and bark of a suspicious dog, came over the water or through the lime avenues with no unpleasing effect upon the wakeful ear, which had been so stunned by the tumult of noon-day as scarcely to distinguish one sound from another amidst the confusion. One fine noon, however, in the summer of 1696, a certain portion of the busiest district of Amsterdam did appear more thronged than the rest. There was a crowd around the door of a handsome house in the Keiser's Graft, or Emperor's-street. The thickly planted limes were so far in leaf as to afford shade from the hot sun, reflected in gleams from the water in the centre upon the glaring white fronts of the houses; and this shade might tempt some to stop in their course, and lounge: but there were many who were no loungers flocking to the spot, and making their way into the house, or stationing themselves on the painted bench outside till they should receive a summons from within.