ROBERTSON, J. A Treatise of such Mathematical Instruments as are usually put into a Portable Case.. London: T. Heath and J. Nourse, 1757 (Second edition, with many Additions). xx, 188pp. Folding diagrA Treatise of such Mathematical Instruments as are usually put into a Portable Case, containing their various uses in Arithmetic, Geometry, Trigonometry, Architecture, Surveying, Gunnery, etc. With a Short Account of the Authors who have treated on the Proportional Compasses and Sector. To which is now added an Appendix containing, the Description and Use of the Gunners Callipers. Professionally rebacked, with raised bands, gilt title lettering and rules William Beckford bookplate on front paste-down some staining to bottom half of folding frontis., title, prelims., and first few gatherings staining and a little periodic soiling or foxing continues throughout, although mostly very light there are 9 different folding diagrams (including the frontispiece), although 10 altogether as plate VIII has been inserted twice at the end there is also some staining to this last plate.