Philosophical Transactions giving some account of the present undertakings, studies and labours of the ingenious in many considerable parts of the world. Vol XX for the years 1698. [BOUND WITH] Vol XXI for the years 1699. Numbers 236-259. Prelims to Vol XXI bound before page 407 [ie before issue 259]. Errors in pagination to Vol XXI, but text continuous. First edition. 4to. Vol XX Pp [iv], 468 [iv], 10 plates and two folding tables. Vol XXI [vi] 442 [vi]. 11 plates and two folding tables. Bookplate of N Vansittard to front paste down, booklabel Winnard s bequest Free Public Library to front pastedown. Twenty four issues, complete of these early two volumes, rare so. Amongst the important articles in these issues are the first description of an effective steam pump: An Account of Mr Savery s Engine, for raising water by the help of fire (issue 253). They contain also amongst many others a dissection of the American opossum from Virginia by Tyson (issue 239), a method of extracting the root of an infinite Equation by Moivre (issue 240) a description of a triple rainbow by Halley (issue 240), observations on Giants Causeway (issue 241), some thoughts on vegetation by John Woodward (issue 244), a description of Loch Ness, explaining how deep it is [but, alas, no mention of the monster] (issue 254), correspondence between Wallis and Leibnitz (issue 255), a discourse on coffee by John Houghton (issue 256), A calculation of the credibility of human testimony (issue 257), on the discovery of the bulbourethral glands by Cowper (also known as Cowpers glands), and also a letter by Benjamin Woodroose concerning several observations in Maryland (issue 259). They also contain an objection to Leeuwenhoek s assertion on the generative properties of male semen by Dr Lister (issue 244), and Leeuwenhoek s reply (in issue 255), in which there are two articles from him: i) containing his answers to objections made to his opinions, and ii) concerning the Animalcula in Semine humano, in which he argues from his own experimental researches that the shape of sperm does not resemble a homunculus.