South African Class 15F 4-8-2 South African Class 15F 4-8-2 The South African Railways Class 15F 4-8-2 of 1938 was a steam locomotive. The Class 15F was the most numerous steam locomotive class in South African Railways service. Between 1938 and 1948, 255 of these locomotives with a 4-8-2 Mountain type wheel arrangement entered service. The Class 15F 4-8-2 Mountain type steam locomotive was designed by W.A.J. Day, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1936 to 1939, based on the design of the Class 15E by his predecessor, A.G. Watson, and later modified again by his successor, M.M. Loubser. It
Minim (unit) size of a drop can vary considerably depending upon the viscosity and specific gravity of the liquid. (At the time, the phenomenon of surface tension was not well understood.) The minim, on the other hand, was measured with a graduated glass tube known as a "minimometer", later known as the minim-tube. The minim-tube was a type of graduated pipette, a device invented in 1791 by François-Antoine-Henri Descroizilles. Apothecaries' measures are fully defined in the United Kingdom's Weights and Measures Act of 1878, but the UK's 1963 Weights and Measures Act provided for the abolition of the minim, fluid scruple, and