title: Scale design of metric rules and slide rules.
abstract: The design of metric draughtsmen's scale rules is discussed as if they were indicating instruments with straight scales. A minimum distance between marks of 1 mm is recommended and some suggestions for experimental designs are made. Slide rules are also considered with a view to improving their legibility.
authors.affiliation: Formerly of the Applied Psychology Unit, Admiralty Research Laboratory, Teddington, Middlesex.
authors.forename: H C
authors.initials: HC
authors.lastname: Stockbridge
authors.forename: R J
authors.initials: RJ
authors.lastname: Miles