They waited a few moments, but were very uneasy about the stones, and soon after the last kernels of corn had disappeared from the hopper, they pulled the ash pin to let the gate fall. It was then discovered that from some cause the gate would not drop. The boys thumped and rattled it. But the water still poured down on the wheel. By this time the meal had run nearly all out of the millstones and they revolved more rapidly. The young millers were now a good deal alarmed, and, running out, climbed up the dam and looked into the flume, to see what was the matter with their gate. "It's an old shingle-bolt!" shouted Jock, "that's floated down the pond! It's got sucked in under the gate and holds it up! Fetch the pike-pole, George!" George ran to get the pike-pole; and for some moments they tried to push, or pull, the block out. But it was wedged fast and the in-draught of the water held it firmly in the aperture beneath the gate. It was impossible to reach it with anything save the pike-pole, for the water in the flume over it was four or five feet deep. Meantime the old mill was running amuck inside. The water-wheel was turning swiftly and the millstone was whirling like a buzz saw. After every few seconds we could hear it graze down against the nether stone with an ugly sound; and then there would fly up a powerful odor of ozone. Jock and George, finding that they could not shut the gate, came rushing into the mill again in still greater excitement. "The stones'll be spoilt!" Jock exclaimed. "We must get them to grinding something." He ran to the little bin of about a bushel of corn where the old miller kept his toll and where they had put the toll from our bags. This was hurriedly flung into the hopper and came through into the meal-box at a great rate. It checked the speed in a measure, however, and we took breath a little. "You had better keep the mill grinding till the pond runs out," Addison advised. "I would," replied Jock, "but that's all the grain there is here." It was evident that the mill must be kept grinding at something or other, or it would grind itself. It would not answer to put in pebbles. Ad suggested chips from the wood yard; and George set off on a run to fetch a basketful of chips to grind; but while he was gone, Jock bethought himself of a pile of corncobs in one corner of the mill; and we hastily gathered up a half-bushel measureful. They were old dry cobs and very hard. "Not too fast with them!" Jock cautioned. "Only a few at a time!" By throwing in a handful at a time, we reduced the speed of the stones gradually, and then suddenly piling in a peck or more slowed it down till it fairly came to a standstill, glutted with cobs. The water-wheel had stopped, although the water was still pouring down upon it; and in that condition we left it, with the miller boys peeping about the flume and the millstones and exclaiming to each other, "What'll Pa say when he gets back!"