354 Dr G.Wilson on the Early History of the Air-Pump. 



the pislous ; but in their mutual twin dependence, and in the 

 arrangement of the self-acting valves. To Papin all this 

 merit belongs. Whether he was the inventor of the instru- 

 ment he shewed to Boyle, I cannot positively affirm. Boyle 

 understood that he was, and he certainly ranks before any 

 English constructor of a double-barrelled air-pump. Into 

 the history of foreign improvements on the instrument I do 

 not at present enter. Winkler, who was professor of natu- 

 ral philosophy at Leipsic, in the middle of last century, in his 

 Elements of Natural Philosophy, gives a good sketch of the 

 history of the air-pump.* Hauksbee, and Leupold, of Leip- 

 sic, who was contemporary with Hauksbee, are the only par- 

 ties to whom Winkler refers as having a claim to be con- 

 sidered inventors of the double air-pump. He makes no al- 

 lusion to Papin's. M. Libesf states, that Papin and Hauks- 

 bee are the only claimants of the double pump ; and that 

 Cotes, of Cambridge, a contemporary of Hauksbee, attributed 

 the invention to Papin. There should thus seem to be no 

 foreign claimant against Papin, and no known English one 

 but Hauksbee, whose pump was constructed some twenty 

 years after Papin had devised and published an account of 

 his, which, it seems impossible to doubt, must have been 

 known to Hauksbee.J 



The reader will now understand why I should think it in 

 the highest degree improbable that the double-barrelled 

 air-pump of the Royal Society belonged to Boyle. It is, 

 possibly, a relic of Hooke, and of the seventeenth century ; 

 but more probably a memento of Hauksbee, and belonging 

 to the eighteenth century. 



* English Translation, 1767, vol. i., pp. 116-119. 



t Hint, des Progres de la Physique, 1810-1812, tome iii., p. 56. 



"l Libes exaggerates Hauksbee's merits, ascribing to him the device of 

 " une platine ajout6e a Tinstrunient" (Op. et loc. cit.). The air-pump jpZafe, as 

 I have fully pointed out, was an appendage of the second English air-pump of 

 1667. 



