Engraved Plate CCXXXVII by John Farey from David Brewster’s Edinburgh Encyclopaedia (1808-30)… . Note (7) the folding pillar compasses. (8) the turn-about compasses. (I2) a double bar parallel rule, (13) a beam compass and fittings, (14) Farey’s device for striking curves of high radius. (15-17) a scale rule with offsets shown together with Farey’s bevel, (19) a drawing board set up with Farey’s tee-square and bevel shown with drawing pins holding down the drawing paper, (20-22) Farey’s device for dividing circles, (23) Mr Donkin’s steel pen, (24) a ruling pen with split handle for easy cleaning. Science Museum Library, London.
Parallel rules: four versions of 6-inch parallel rules - (A) plain, (D) with scissored links, (C) double parallel rule with parallel links, (D) double rule with scissored links; (E) a 12-inch parallel rolling rule; (F), (G) and (H) parallel rule/set square for setting off right angles; (I), (K) and (L) protracting parallel rule for setting off any angle; (M), (N) and (O) Haywood’s parallel rule which resembles a gauge. Pl.II from the revised edition (1797) of George Adams the Younger’s Geometrical and Graphical Essays.
Engraving from George Adams the Younger’s Geometrical and Graphical Essays dated December 1796; Fig. 2 shows Adams’ perspective apparatus … which incorporates three rollers to operate the drawing point suspended by wires from a counter-balanced metal frame.
Gaspard Monge’s universal spatial matrix of descriptive geometry (1790s), from R. G. Robertson, Descriptive Geometry … Monge’s spatial matrix was construed as an a priori entity where all concrete phenomena could be objectively described by means of mathematical coordinates in three orthogonal dimensions.
Courtesy of Sir Isaac Pitman and Sons Ltd.
Architectural Representation and the Perspective Hinge, Perez-Gomez A & Pelletier L, 1997
Ellipsograph of brass and steel inscribed ‘Gourdin á Paris’ with frame and circular plate designed as a trammel slotted to take the drawing arm; the four adjustable feet at the corners are missing. c. I 790. Museum of the History of Science, Oxford.
Tortoise-shell-covered small pocket case with decorative silver mounts which contains silver instruments; the 4½-inch protractor is signed ‘E. Nairne London’. This small set includes a pair of large compasses with inserts for pencil and ink (note the link piece for their storage), a pair of small bows for ink, a ruling pen with turned handle with the protracting pin shown exposed and a silver mounted pencil. Case: 5in (127mm) long. c.I770. Andrew Alpern Collection, New York.
A black fishskin silver mounted pocket case containing a complete set of silver drawing instruments; the parallel rule and sector are signed ‘Thomas Wright’. Intended for a military engineer since gunners’ callipers are included.c. I740. National Maritime Museum, Greenwich.
A parallel rule of mahogany with brass scissored links and slotted plate with knobs to adjust the distance between the rules, signed ‘T Heath Fecit’. Length 14in (362 mm). Mid-18th century. Private collection.