Saturday, 7 March 2009
How did a farmer weigh his cow sheep or pig in the field?
In the nineteenth century, how did a farmer weigh his livestock in the field? He might have used a clever little slide rule known as "The Cattle Gauge & Key to the Weighing Machine" arranged by J Ewart, Newcastle on Tyne. These rules were often manufactured by James Tree of 22, Charlotte Street, Blackfriars Road, London. The method used involved measuring the length and girth of the animal and using a ready reckoner on the rule, giving percentage values of meat on the carcass, to calculate the weight using a series of gauge points. The rules are made mainly from box but sometimes with ivory slides and occasionally completely from ivory. The Tree family made rules at Charlotte Street from 1832-1895, according to the Directory of British Scientific Instrument Makers 1550-1851, but these rules probably date from the second quarter of the nineteenth century. Although this rule is uncommon, its just the sort of thing that turns up at the fair. Several dealers specialise in slide rules and calculators, notably David & Yola Coffeen, from Tesseract , Peter Delehar , and Desmond Squire .
Posted by Fletcher Wallis at 18:06