This brass instrument with steel points is contained in a cylindrical metal case and provided with steel accessories such as straight and curved points, pencil-holders, paper cutters and so on. Each required accessory could be inserted into the brass legs and held by a screw. In its various permutations, this instrument could serve as compasses, as dividers, as a caliper and for marking up drawings.
The instrument is known as the ‘Michelangelo’ compasses, because it was found amongst the possessions of Michelangelo Buonarrotti.
Perspective apparatus designed by the engineer James Watt and made by him in Glasgow in 1765. This is an ingenious device, easily transportable, for use in external perspectives. The apparatus folds away into a fitted hardwood case, which also forms the drawing board; its stand fits together to form a walking stick. Science Museum, London.
Volute compasses in silver made for George III and signed ‘D. Lyle 1760’. These consist of a beam divided into inches similar to a beam compass, but with a helical drum unit fixed to the plane of the beam. A catgut thread connects the end of the helical curved spring to the pencil-holder. The beam is rotated with the centre fixed, and the drawing point traces a spiral curve. Alternative helical drums are included in the shagreen-covered fitted case for drawing different spiral curves. Beam length 7½in (190 mm). George IIICollection, Science Museum, London.
A small magazine case of drawing instruments made by George Adams the Elder. The Sheraton-style case is of oak and mahogany lined with green velvet with the brass instruments fitted to the lid and to the base. This set includes a semi-elliptical trammel and drawing arm, proportional compasses, 6-inch pair of compasses and a 9-inch protractor combined with scales, medium dividers, small bows, and three sizes of ruling pens. There is a 9-inch sector, 6-inch callipers and a 6-inch parallel rule to the lid (not shown). The gunners’ callipers and the protractor are signed and the sector is fully signed ‘Improved & Made by GEORGE ADAMS at Tycho Brahes’ Head in Fleet Street. LONDON’, which dates the case c. I760. Science Museum, London.
At the end of every summer, my tools undergo a ritual cleaning to clear off the field season’s dirt and grime. It also gives me a chance to replace broken or lost tools. My papers and notebooks are usually kept in a separate bag to protect them from dirt and water.
Eighteenth-century engraving showing a building under construction and the architect discussing some detail with his client. The accompanying verse is taken from Pope’s Epistle to Lord Burlington. 1731. Mansell Collection.
Architectonic sector in brass, possibly based on a design described by Revisi Bruti of Vicenza in his treatise of 1627; arranged as a hinged sector with sliding architectonic plates or arcs, the latter finely engraved with scales for calculating all the elements which make up the five Classical orders of architecture. Maker Culpeper? Length 11½in (290 mm); diam 6½in (165 mm). c.1730. Museum of the History of Science. Oxford.