ables in which a number of horses, mules, and donkeys were kept. Before them was the main gallery, about eight feet high and the same wide, arched over with bricks four thick, and extending three miles away from the mouth of the pit. Out of it for its whole length opened shorter galleries or side galleries where the coals were now being won. In all of them rails were laid down for the waggons to run on, and on each side were seams of coal, in some places narrow near the top, in others close to the ground, and in some there was coal from the top to the bottom. At the entrance of these side galleries were doors which had generally to be kept shut, and were only opened when the waggons, loaded with coal or returning empty, had to pass through. After Simon and Mark had proceeded a couple of miles along the main gallery, they stopped at one of these doors. "This is to be your post, Mark," said Simon.
"When you hear the waggon coming, you are to open the door, and as soon as it is passed to shut it. Mind you