Wash out sand and dirt occasionally, a strainer located in the pump line will help to keep the jacket clear and free from foreign matter. If a solution of carbonate of soda, or lye, and water are allowed to stand in the cylinder over night, the deposit will be softened and the work with the chisel will be made much easier. If a radiator is used (automobile or aero engine) the deposit can be removed with soda, never use acid, lye, or kerosene in a radiator or with an engine with a sheet metal water jacket. =Obstructions in Water Pipes.= Poor water circulation may be caused by sand, particles of scale, etc., clogging the water pipes, or by the deterioration of the inner walls of the rubber hose connections. Sometimes a layer of the rubber, or fabric of the hose may loosen from the rest and the ragged end may obstruct the passage. A sharp bend in a rubber hose may result in a “kink” and entirely close the opening. The packing in a joint may swell, or a washer may not have the opening cut large enough, either case will result in a poor circulation. Sediment is particularly liable to collect or form in a pocket, pipe elbow, or in the jacket opposite the pipe opening. Oil should be kept off of rubber hose connections as it will cause them to deteriorate rapidly, this may finally result in water circulation troubles. Rubber pipe joints between the engine and the radiator or tanks are advisable as they do not transmit the vibration of the engine, and hence reduce the strain on the piping. A strainer should be provided in order to reduce the amount of foreign material in the water. =Radiators.= A clogged radiator will give the same results as a clogged jacket with the exception that steam will issue from the radiator if the circulation is not perfect. If the radiator becomes warm over its entire surface it is evident that the water is circulating, the temperature being a rough index of the freedom of the water, or the interior condition of the surfaces. A leaking radiator may be temporarily repaired with a piece of chewing gum. Should the radiator be hot and steaming at the top and remain cold at the bottom for a time, it shows that the water is not circulating and that the jackets on the cylinders are full of steam. Such a condition usually is indicative of clogging between the bottom of the radiator and pump, between the pump and bottom of cylinders, or of a defective pump. [Illustration: Natural Gas Plant at Independence, Kansas. Used for Pumping Gas From the Wells to Various Distributing Points. ] Thermo-syphon radiators are more susceptible to the effects of sediment and clogging than those circulated by pumps. A radiator may fail to cool an engine because of a slipping or broken belt driving the fan, or on account of a loose pulley or defective belt tension adjuster. Keep the belt tight. The fan may stick on account of defective bearings. Radiator may be =AIR BOUND=, due to pockets or bends in the piping holding the air.