Comparisons by R. Sheepshanks of individual experimental standard bars made from bronze, brass, copper and iron at various regulated temperatures. Most of the comparisons are with 'Bronze 28', although some are with 'Bronze 12'. The volume also includes statements on the means used to find the exact length of the imperial yard; methods of observations; tables of the co-efficients of the expansion of bronze, brass and iron; a report for the Royal Society; and a list of destinations for the bars.