companies designated for service therein must hunt it up and put it out. The seventh and eighth districts divided the lower part of the city, a little below Canal Street, evenly between them. Then, as the city broadened there, the great, far-spreading space between the East and North Rivers, south of Twenty-second Street, was parcelled off into the third, fourth, fifth, and sixth districts, beginning from the west. These were quite narrow at the south, but flared out north and eastward. Above them, on the east and west sides of the city respectively, lay the first and second districts, the former extending almost to Harlem, which had on Mount Morris its own bell-tower and at its foot a little department of its own. Night and day a single watcher was perched in the glass-enclosed lookout at the summit of each lofty tower, his sole communication with the world below being a speaking-tube to the engine-house at the base and a single wire that connected his "circuit" with the main office at the City Hall, a circuit so limited in its possibilities that it could only administer a single tap at a time upon the tiny gong-bell over the watcher's desk, and finally the big, booming bell that, hanging midway down in the lofty structure, was yet so high above the neighboring roofs and walls that its sound bellowed forth in unimpeded volume. It was struck by a massive swinging hammer, worked by a long steel lever aloft in the watch-tower, the entire apparatus being the design, as were some of the strange-looking engines, of ex-Chief Carson, and one of the greatest treats that Pop's boys could possibly have was to be piloted of a wintry Saturday afternoon or summer evening, by one of their number who had the _open sesame_, up, up the winding stairway, up past the huge, silent monster that hung midway. (You may venture to bet they wasted no time there, but scurried past him, full tilt, lest an alarm should come at the instant and he should suddenly boom forth and stun them with his clamor.) Once well past him, they breathed freer, if harder, for the climb was long, and at last, tapping on a little trap-door, were admitted to the sanctum at the summit, and could gaze in delight and wonderment about them and over the busy, bustling world far, far beneath. Once well above the low ground of Canal Street, the city rose, and from the Hudson to the East River, along about the line of Spring Street, the ground was high, and here was established the inner row of Gotham's picket guards against fire: three tall towers, one away over at Essex Market, on the far east side, guarding the sixth district; one on Marion Street, guarding the lower fourth and fifth; one over at McDougal Street, guarding the lower third. The next post to the northward was at Jefferson Market, on Sixth Avenue, a tall white wooden shaft that seemed to pierce the skies, so low were all the surrounding buildings, and from his eerie at its summit