Rotary Engines, Pumps or Meters. British Letters Patent No. 3316
London: George Edward Eyre and William Spottiswoode, Printers, 1875. Pamphlet. Pamphlet, perhaps disbound from a larger work. 5 pp., plus a large fold out illustrated diagram depicting the invention. A British letters patent issued to Walter Eccleston Bartrum for an invention of improvements on rotary engines, pumps or meters. GOOD..... More