London, at the period of this history, boasted only a single bridge. But that bridge was more remarkable than any the metropolis now possesses. Covered with houses, from one end to the other, this reverend and picturesque structure presented the appearance of a street across the Thames. It was as if Grace-church Street, with all its shops, its magazines, and ceaseless throng of passengers, were stretched from the Middlesex to the Surrey shore. The houses were older, the shops gloomier, and the thoroughfare narrower, it is true; but the bustle, the crowd, the street-like air was the same. Then the bridge had arched gateways, bristling with spikes, and garnished (as all ancient gateways ought to be) with the heads of traitors. In olden days it boasted a chapel, dedicated to Saint Thomas; beneath which there was a crypt curiously constructed amid the arches, where "was sepultured Peter the Chaplain of Colechurch, who began the Stone Bridge at London:" and it still boasted an edifice (though now in rather a tumbledown condition) which had once vied with a palace,--we mean Nonesuch House. The other buildings stood close together in rows; and so valuable was every inch of room accounted, that, in many cases, cellars, and even habitable apartments, were constructed in the solid masonry of the piers. Old London Bridge (the grandsire of the present erection) was supported on nineteen arches, each of which Would a Rialto make for depth and height! The arches stood upon enormous piers; the piers on starlings, or jetties, built far out into the river to break the force of the tide. Roused by Ben's warning, the carpenter looked up and could just perceive the dusky outline of the bridge looming through the darkness, and rendered indistinctly visible by the many lights that twinkled from the windows of the lofty houses. As he gazed at these lights, they suddenly seemed to disappear, and a tremendous shock was felt throughout the frame of the boat. Wood started to his feet. He found that the skiff had been dashed against one of the buttresses of the bridge. "Jump!" cried Ben, in a voice of thunder.