As a rule, curling stones are made of granite or trap, a mixture of felspar and hornblende; therefore to polish them without machinery is very laborious work. Rig up a vertical lathe similar to those used by lapidaries, and place the stone on it, and, while revolving, put coarse emery and water on it, pressing a piece of smooth iron on the stone as it revolves. When all pits and unevennesses are removed, carefully wash away the emery grains and go through the same process with fine emery, removing all scratches left by the former treatment. This process must be gone through with care, as if scratches are not removed it will be impossible to get a good polish. When an even grain, dull polish is obtained, carefully wash again, removing all traces of emery. Fasten a piece of felt to a piece of wood and on it put some putty powder slightly wetted, and apply to the stone until a good polish is obtained. A deal of the rough work might be done in bringing the stones into condition for further grinding if in the first instance they could be slung in front of a grindstone.