FURLONGS PER FORTNIGHT is not an acceptable unit for velocity in the study of physics. This is because such mongrel units do not abet the sort of consistency needed for carrying out scientific research, which is already complicated enough. Instead the Systeme International (SI) dictates a strict code of kilograms, meters, and seconds. Nevertheless, physicists are human and (especially in the largely non-metric US) surround themselves with many non-SI units like miles-per-hour and atmospheres. Robert Romer, editor of the American Journal of Physics, argues that this is inevitable and partly desirable since we all, even scientists, continue to live in a world where BTU's, horsepower, and barrels of oil are still common parlance. (Editorial, AJP, Jan 1999.)