STEAM CYLINDER.
The Steam Cylinder is that part of an engine in which the piston travels; it also contains the steam and exhaust ports and is one of the most expensive, as well as essential, parts of an engine. The cylinder should be made of the best quality of cast iron, and the greatest care taken in boring it perfectly true and round. It should be counter-bored at each end to allow the piston in its travel to overlap at the end of each stroke. Without the counter-bore, a shoulder would be formed at both ends of the cylinder as it became worn by the piston rings, which in time would cause a knock or pound at the end of every stroke; the only remedy being to have the cylinder re-bored.
Special attention should be paid to keeping the cylinder well oiled with the best quality of cylinder oil to prevent it from being cut by the piston rings. If allowed to run dry and cut, it will cause no end of trouble.
The size of cylinder is not always the measure of the power of the engine. The power depends upon the heating surface of the boiler and steam pressure; as the piston speed can always be increased, by running the engine faster, until the maximum evaporating capacity of the boiler is reached.