where:
ET = equivalent temperature (degrees Celsius)
WCF = wind chill factor (Watts per square metre)
SQROOT = square root function
W = wind speed (Km/hr)
T = air temperature (degrees Celsius)
(Source: Weather University of Waterloo)
'The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as in poetry.'