Letter: A kick or judder at the polls

NICHOLAS BAGNALL clearly did not ask an engineer whether 'backlash' is an appropriate word in the cases he cites (Word, 22 May).

A technical dictionary would have told him that backlash is 'lost motion between two elements of a mechanism, ie the amount the first has to move, owing to imperfect connection before communicating its motion to the second'.

Backlash is most commonly noticed when, lifting one's foot off the accelerator at slow speed, a kick or judder is felt, especially with a transmission coming to the end of its life. This is the effect of lost motion when changing from the engine driving the car to the car driving the engine, and is analogous to the electorate's reply to a worn- out government. Normally the politician thinks he is driving the electorate. At election times the elector has a chance to drive for himself and frequently inflicts backlash on his masters. As we shall see on 9 June.

Michael Sibley

Technical editor

'Professional Engineering'

Bury St Edmunds, Suffolk