24^ Of! ihe Antiquity and 



to confi:ru6l thcfe machines, which were called pompes por- 

 tati-ves; and he engaged for a certain fum to keep in repair 

 the feventeen engines which had been purchafed for the ufe 

 of the citv, and to provide and pay the ncccflary workmen. 

 In the year 1722 the number was increafed to thirty, which 

 were diftributed in feveral quarters of the city ; and the con- 

 traftors received annually at that time 20,000 livres. The 

 city, however, bcfides the thirty royal engines, had others 

 which belonged to the hotel de ville, with which the fieur 

 Duperrier had nothinij: to do *. 



In the middle of the fixteenth century thefc machines 

 were certainly ftill very imperfeft. They had neither an air 

 chamber nor buckets, and required a great many men to 

 work them. They con(i(ted onlv of a fucking pump and for- 

 cing pump united, which forced ihe water out in fpurts, and 

 with continual interruptions. Such machines in moving the 

 lever experience a ftoppage, during which no water is forced 

 out; and, as the pipe is lixed, it cannot convey the water 

 into a houfe on fire, though it may reach a fire at no great 

 diftance viherc there are doors and \^indow3 to afford it a 

 pafTaire. At the fame time, the workmen are liable to be 

 cruflied by the {all of the houfcs, and on that account mu(t 

 keep from them. Ilautfch, however, had given to his en- 

 gine a flexible pipe, which could be turned to any fide as 

 might be necefiary; but not an air-chamber, which Schott 

 certainly would have defcribed. f2ven in Belidor's time, the 

 fire engines in France were of no other kind. In the year 

 1760 thefe improved machines were ufed only in England; 

 atleaft profcfibr Bufch f concludes fo from this circumltance, 

 that Fergufon confiders Newfham's engine, which threw the 

 water out in a continued flream, as a new invention. 



It is not with certainty known who fird conceived the 

 idea' of conftrufting an engine with an air-chamber, in 

 which the included air, by comprefling the water, forces it 

 out in a continued (iream. According to a conjefture of 

 Perrault, it would appear that Vitruvius feems to fpeak of a 

 fimilar conftruftion; but Perrault himfelf acknowledges that 

 this obfcure paffiige J can be explained in a different manner. 

 The air-cham.ber in its a6tion has however fome refemblance 

 to Hero's fountain, in which the air, being comprefTed by 

 the water, forces the water out §. 



■■■ Continuation dn Traire dc !a Poljce, &c. p. 157. 

 + Verluch einer Mathcmatik lUiii Nutien qnd Vergnugen, Hamburg 

 1791. Svo. p. 3v6. 

 j Lib. X. c. 12. 

 ^ Spiritalia, xxxvi< p. C5. 



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