known description of a ship's log and line, which he attributes to Humprey Cole, an officer of the Tower Mint. The 75th device on the list is a description of a night signal or early semaphore system to be used between people on distant ships who had previously decided on a code consisting of a series of lights and fashion of standing. The 110th entry is what seems to be a type of telescope. The device was said to have been employed by mathematician and surveyor Leonard Digges and Bourne was asked to investigate it by Queen Elizabeth I's chief advisor Lord Burghley. Bourne's is the best description of it, and from his writing it seemed to consist of peering into a large curved mirror that reflected the image produced by a large lens (Bourne noted in his report that the device worked but had a very narrow field of view, making impractical in military applications). This "backwards" reflecting telescope predates the earliest known working telescope by 30 years but its unwieldy nature seems to have kept it from being developed. Partial list of publications An Almanac and Prognostication for Three Years, 1571 William Bourns booke of artillery, 1572 (draft manuscript) Treasure for Travellers, 1572/3 Art of Shooting in Great Ordnance, 1572/3 A Regiment for the Sea, 1574 (11 English editions from 1574 to 1631, at least 3 Dutch editions starting in 1594) A Booke called the Treasure for Traueilers, 1578 (republished in 1641 as A Mate for Mariners) Inventions or Devises. Very Necessary for all Generalles and Captaines, as wel by Sea as by Land, 1578 The Arte of Shooting in Great Ordinance, 1578, 1587, 1643 "On Optical Glasses," transcribed manuscript published in Halliwell's Rara Mathematica. References External links Bourne's bibliography, Museum of the History of Science, University of Oxford webpages 16th-century English mathematicians 1530s births 1582 deaths People from Gravesend, Kent