Reverse-Printed Paper Instruments (With a Note on the First Slide Rule)

摘要

When David Bryden published his exceptionally useful essay 'The Instrument Maker and the Printer: Paper Instruments Made in Seventeenth Century London' (1997), there was one class of print that left him puzzled: 'Another practice to be aware of,' he wrote, 'is the paper instrument that has been made by using a flat engraved brass instrument as a printing plate. Whether this was simply to record a piece of particularly fine or laborious workmanship for future reference in the workshop, and as a sample which could be shown to customers, or some other explanation, remains speculative so long as so few examples are known.' At that point Bryden could list two reverse-printed paper instruments, both held at the Museum of the History of Science, Oxford: a print from the dial-plate of an early-eighteenth century John Rowley horizontal dial (inv. no. 13309); and one from the 'Rojas' projection on a large 1659 astrolabe by Henry Sutton - the latter, remarkably, stored at the MHS alongside the instrument from which it was pulled (Figs la & b; inv. nos. 56420 and 51786, respectively).