Here is an idea which any smart boy can put into practise in his workshop. The idea is to use part of an old bicycle which is no longer suitable for the road to do work by turning a grinding wheel or polisher. The frame is mounted, as shown, with the back spindle mounted on the tops of two wooden posts driven firmly and solidly into the ground. A small pulley, such as a cotton reel, is fixed firmly to the axle on which the grinding wheel turns. Such grinding wheels can be bought at many of the cheap stores that exist in every town. A cord about as thick as a black lead pencil provides the necessary belt, the ends of which must be joined neatly. A cotton reel fixed between the bars under the seat makes an intermediate pulley to keep the belt away from the trousers of the operator. The polisher can be made by fixing any old rag stuff on a wooden disc, two flat discs of wood being placed on each side to hold the rag in position.