MICROFICHE REFERENCE LIBFUUW - Cd3wd.com

Several other pumps were developed during this time, but the widespreaduse of direct-acting pumps and growing popularity of roto-dynamicpumps usually suppressed their development. However, one such uniquepump was Humphrey’s gas pump which was developed from the pr ciple ofJohn Barber’s 1791 explosion pump.In 1939, Water Supply Engineering discusses advance> pumping overthe past decade which includethe development of submeT,-: ii,. .; pumps,invention of vertical, helical pumps, development of .iter lubricatedvertical pumps, improvement of centrifugal efficiencies to as high as 93percent, and increasing use of close-coupled units, as well as noting thatII . ..electric (power) is holding its own...,” but diesel engines arebecoming more popular.1.3 Current TrendsThe state of water lifters in the world today is highly diversified,both in levels of development and variety of designs. In some areas ofthe world,designated community members, using only hollow bamboo polesfor containers, spend most of every day walking miles to distant watersources and returning with barely enough water for minimal domestic purposes--let along irrigation. Meanwhile--typical of many unevenly distributedtechnical and natural resources --other areas have thousands of types andsizes of pumps with which to lift and transport ample water for all formsof domes tic, industrial, recreational, and agricultural uses.In industrialized nations, water lifting is a highly technical andcompetitive industry. The United States has well over 500 pump manufac-turers (Thomas Publishing, 1974) with almost countless numbers of acLossorysuppliers, well contractors, and complementary industries (e.g., pipes,