The Cambridge Guide to Australian English Usage - Noel's ESL ...

imperial weights and measures
imperial, imperious or imperative With the decline of empires and
emperors, there’s less for imperial to do. It remains as a monument to former
empires in Imperial College London, and to former emperors in the Imperial Palace
to be visited by tourists in China and Japan. This is not to say that imperialism
itself is dead, but rather that it’s not now linked with recognised empires.
In Australia, the use of Imperial with a capital I has always been in connection
with the British Empire, as it was in AIF (the abbreviation for the Australian
Imperial Force) which served in both World Wars. With the commutation of the
British Empire into the (British) Commonwealth, most Imperial institutions have
disappeared, or been renamed. The most generally known Imperial institution to
survive is the imperial system of weights and measures, on which see the next entry.
Neither imperious nor imperative have any connection with empires. Yet
imperious implies the will to make others do your bidding, as in:
The imperious voice of the matron resounded ahead of her as she swept
down the corridor.
Imperious is usually applied to aspects of people’s behavior, whereas imperative
is mostly used of circumstances which force us to do something:
It’s imperative that they decide before the next election.
For the grammatical use of imperative, see under that heading.
imperial weights and measures The imperial system of weights and
measures was formerly used in Australia, and continues to be used in the US,
and to some extent in Britain. In Australia it was officially replaced by the metric
system in 1970, and in New Zealand in 1987. Younger people absorb the metric
system as part of their schooling, even if older people still calibrate things in imperial
measures, estimating distances in miles, and human weight in pounds and stones.
The most common terms in the imperial system include:
for length: inch foot yard chain furlong mile
for mass: ounce pound stone hundredweight ton
for volume: fluid ounce pint quart gallon
Some of those terms linger in common idiom:
a six footer
wouldn’t budge an inch
miles from anywhere
drinking whisky by the gallon
Imperial measures persist in a number of specialised fields the world over. A tennis
net is set at 3 feet or 1 yard (= 0.914 metres) above the ground, and a cricket pitch
is still a chain or 22 yards in length (= 20.12 m). Printers calculate the dimensions
of a piece of printed text in picas, which measure just on one sixth of an inch; and
the screws used by engineers and carpenters are normally calibrated in terms of so
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