South African Class 19D 4-8-2 South African Class 19D 4-8-2 The South African Railways Class 19D 4-8-2 of 1937 was a steam locomotive. Between 1937 and 1949, the South African Railways placed 235 Class 19D steam locomotives with a 4-8-2 Mountain type wheel arrangement in service. Between 1951 and 1955, 33 more were built for other operators like the Rhodesia and Angolan railways and the Nkana and Wankie mines, which makes the Class 19D the most numerous South African steam locomotive type ever built. The Class 19D 4-8-2 steam locomotive was the final development of the Class 19 family of locomotives. At the request of
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