Engine, HIGH

-PRESSURE. Term formerly synonymous with Non-Condensing Engine, and often so used to-day. In early practice, when weak boilers admitted only of very low steam pre ures, an engine which did not condense its steam would have to carry a higher steam-pre ure than those which did most of their work on the vacuum in the cylinder after condensation. Hence in those days non-condensing engines were high-pre ure engines, and the terms could be used indifferently. Now, however, many condensing-engines carry as high steam pre ures as any other kind, and high-pre ure is not synonymous with non-condensing, except in the compound engine.