Castings capable of withstanding high pressures can be made with copper-rich aluminum-bronzes. These alloys have so small a freezing interval that no segregation takes place even when cast in sand. They are easily prepared, resist corrosion by fresh and sea water, and possess considerable tenacity and ductility, the former increasing and the latter decreasing with the increased content of aluminum. Experiments with alloys containing 9 to 11. 5 per cent. of aluminum showed that simple cylinders could be cast, both in chill and sand moulds, capable of holding pressures of 15 to 2o tons per square inch. To make a filore complicated casting, such as an hydraulic valve block, consisting of a lug, a barrel and a base-plate, such as is used in high-pressure pumps, it is necessary to observe the foUowing precautions to obtain sound castings. The molten metal should remain in the crucible as long as possible before pouring, which should be done at about I IOO ยฐ C. The metal should be poured very slowly and should enter the mould at the lowest possible point. It is preferable to face the mould with a somewhat coarse sand, and the surface of the lower part of the mould should be dried. Several castings have been kept for a year or two without deterioration" and have been tested for a long period with high-pressure steam under service conditions, quite satisfactorily.