A happy balance between imperial and metric
SIR – Mike Cuddeford (Letters, April 9) says we should go metric. But why get rid of the imperial system?
Both systems work well for different things. The aviation industry uses feet to measure altitude because it has done so since before the Second World War, and the metre is too large a unit for the accuracy required.
On the other hand, for mechanical purposes, the millimetre is a much better way to measure small lengths. Richard Statham Langport, Somerset SIR – Metric measurements and decimal currency are well-suited for calculating costs and quantities in the construction industry. However, it will be a long time before we stop going to builders’ merchants and asking for three metres of four-by-two. Robin Welland-Jones Bentley, Hampshire SIR – Mr Cuddeford is wrong to say that imperial measurements are not taught in school. Pupils are expected to understand all measures in use.
As for the imperial system being “arcane”, he should know that the goalmouth in football is eight yards wide, the crossbar eight feet high and the penalty spot 12 yards from the goalmouth. Highway signs are expressed in miles, yards and feet. Furthermore, ask any youngster his or her height and the chances are that it will be expressed in feet and inches.
If the Welsh can cope with two languages, and the Swiss with three or four, then surely we can cope with two measurement systems. R B Tubb Thatcham, Berkshire SIR – In order to interpret history before the Seventies (and especially the deep past), a knowledge of imperial units is needed. For instance, Alfred the Great ordered that his burhs should be defended using four soldiers for every pole on the walls. To understand this, one needs to know that a tenth of a furlong is a chain (22 yards, the length of a cricket pitch) and that a quarter of a chain is a pole, also known as a rod or a perch.
Thus Alfred required four men to defend five and a half yards: a demand which would have placed huge stress on the limited manpower of Wessex. Robin Nonhebel Swanage, Dorset