Chris wrote in USMA 22958:
They therefore determined to review the metric 'system' (which was no longer really a system, in the same way that imperial units do not constitute a system) and SI was the result of the overhaul.Chris
The term "metric" has applied to several systems, all logically based. They included: centimetre-gram-second, metre-tonne-second, metre-kilogram-xecond, metre-kilogram(force)-second, metre-kilogram-second-ampere now known as SI. All these were "systems", but only SI is "coherent" in the sense that "1" is the only numeric factor in the definitions of the units. By that definition, litre, tonne, and hectare are not SI units although they are certainly metric.
Joseph B. Reid
17 Glebe Road West
Toronto M5P 1C8 Telephone 416-486-6071
