A wooden building forty feet high, and provided with doors and windows exactly like a three-story house, is put up in the schoolyard, and it is with this building that the lessons are given. Every Thursday afternoon an imaginary fire takes place in it. The hose is run out, the ladders are raised, and the lads go to work with a will, saving imaginary lives, and fighting imaginary flames. Each week some new complication is supposed to take place, and some extra machine has to be brought into use, until by the end of the school term they can handle every machine and ladder with the greatest ease. When first the fire drill was introduced into the school, the boys were not obliged to take the study unless they wanted to; but it has become so popular that they are eager and anxious to take it, and now is part of the regular course of the school for all boys who are strong enough to stand the hard work it necessitates. * * * * * Some time ago we talked about the moving of the village of Katonah. Our friends in California can do better than that. While New York moves houses, California moves mountains. A dam is being built at San Diego, Cal., to gather water for the city. Where the water supply for a city is not quite sufficient, darns are often built, to stop small rivers from flowing away to waste; and the water gathered by the barrier of wood, stone, or earth, as the case may be, is turned into the city to be used by the people. In the San Diego work, a huge mass of rocky hillside overhung the canon which was to be dammed, and at the bottom of which the river flowed. A canon is, as you doubtless know, a deep gorge or ravine, formed by the river that flows through it, and which little by little has worn away its bed until it has cut deep down into the heart of the land, hundreds of feet below its original level. As we have said, the plan for the San Diego work was to build a dam across the canon, and keep the waters from flowing away. The engineers thought that if they could only take this huge mass of rocky hill and drop it into the canon, it would make their work very much easier, as the task of getting enough stone down to the bottom of the gorge to build their dam was by no means an easy one. They thought the matter out, and finally decided to try and move the mountain-side into the canon. They laid their plans, and for two months were busy preparing for the great move. They tunnelled the hillside in all directions over the section which they desired to move, and in these tunnels laid mines of giant powder or dynamite. These mines they connected with electric wires, and when all was ready, the various wires were gathered into one bunch, and taken across the gorge that was to be filled up.