3/8 



NATURE 



\August 25, i88r 



from a summary of it scribbled in Iris own handwriting 

 upon the back of Papin's letter. He first congratulates 

 Papin on having set himself to this work ; expresses his 

 fears lest the direct pressure of expanding steam should 

 produce explosions ; and then suggests, " pour faciliter le 

 chariotage," an idea of his own (derived, he says, from the 

 air-pump), that the steam which is to exert pressure 

 should be introduced into a cylinder into which is fitted a 

 second one, after the manner in which our modern gaso- 

 meters fit into their cylindrical pits, the whole being ren- 

 dered steam-tight by mercury. Papin, replying in August, 

 announces that his machine has raised water to the height 

 of 70 feet. He only half approves Leibniz's suggestion 

 on account of the probable friction between the internal 

 cylinders. To this Leibniz retorts that while the friction 

 increases with the diameter of the piston of a pump, the 

 pressure increases as the square of the diameter. The 

 matter seems to have dropped at this stage for three 

 years. In 1702 Papin, still at Cassel, announces to 

 Leibniz that he has invented a steam ballista, " an in- 

 vention to facilitate the capture cf the strongest places," 

 which " will reduce France to make most promptly a 

 durable peace ! " This invention was a cylinder 5 inches 

 in diameter filled with a piston connected to pivoted 

 lever, which on the descent of the piston on the con- 

 densing of the steam below it would project a stone 

 weighing 2 lbs. to a distance of 40 feet. (A similar 

 ballista, unknown to Papin, had been suggested by von 

 Guericke, in 1672, in his Experivunta Nova.) 



Early in January, 1705, Leibniz sent to Papin a sketch 

 of Savery's engine for raising water. This set Papin with 

 renewed vigour to work, besides stimulating to emulation 

 the breast of his patron, the Landgrave of Cassel. After 

 some consideration he pronounced in another letter to 

 Leibniz that he would surpass Savery's invention. He 

 related how he had thought it best not to let the steam 

 act directly against the surface of the water (as in Savery's 

 machine), but that the pressure of the steam should be 

 imparted to the water through the intermediation of a 

 piston whose surface, becoming hot, would not produce 

 condensation : and he added that experiment had proved 

 the conjecture to be sound. His great difficulty now was, 

 not to make pistons fit accurately, but to construct tubes 

 sufficiently strong to bear the pressure of such columns 

 of water as he wished to raise. Leibniz congratulated 

 him when replying in August, and advised him not to try 

 to force water high, but rather to lift it by a series of pumps, 

 each drawing 30 feet, a suggestion which Papin on his part 

 rebutted by observing that one force-pump driving water 

 500 feet high was more economical than ten pumps, each 

 raising the water 50 feet. He further lets Leibniz know 

 that he hopes to do away with the delay of letting the 

 cylinder of his engine cool between each stroke (thevery first 

 of the improvements subsequently made by Watt), and 

 that he has some ideas about the transmission of power 

 to a distance, with which problem however he thinks it 

 useless to concern himself, "because by means of the 

 heat-engine one can produce, everywhere where one will, 

 so much power, and so cheaply, that it would be a super- 

 fluous expense to carry it elsewhere." Strange commen- 

 tary, indeed, on the present eager strife of inventors to 

 supersede steam by the electric transmission of power ! 

 On October 19 he writes again that he is almost satisfied 



with his engine, which, though having but one cylinder 

 and two valves, yet furnishes a continuous jet, surpassing 

 Savery's machine, which had two pressure- vessels and 

 four valves : he is only waiting the Landgrave's orders as 

 to how he shall apply his engine to drive a mill. On the 

 last day of the year 1705 he declares to Leibniz his 

 intention of propelling vessels by steam, as he is per- 

 suaded that by this means one could have vessels which 

 would follow their course correctly in spite of tempests and 

 adverse winds. At this idea he laboured diligently for the 

 next two years — in fact, so long as he continued to re. 

 main at Cassel — his devotion to the object in hand 

 being remitted only for the sake of his correspondence 

 and for the work of publishing his treatise, the " Ars 

 Nova," in which his high-pressure boiler and its applica- 

 tions are described. It was towards the close of this time 

 that (on February 4, 1707) he communicated to Leibniz 

 the first suggestion of a hot-air engine, afterwards realised 

 by Stirling and Ericssen. He was now preparing to leave 

 Cassel, where the patronage of the Landgrave had grown 

 on the one hand slack, on the other irksome, in order to 

 regain the more congenial atmosphere of London and of 

 the Royal Society. He strained every nerve and spent 

 all his little resources to accomplish the building of the 

 steam-propelled boat by which his return to England was 

 to be made famous. He was certain that by this means 

 two men on board his boat might do more than a hundred 

 rowers could. In July and August of that year he made 

 diligent efforts to obtain permission to descend the river 

 vid Miinden and Bremen into the Veser, permission 

 which was finally granted by the Elector of Hanover, in 

 spite of the monopoly possessed by the guild of boatmen 

 of Miinden to pass boats from the Fulde into the Veser. 

 With a boatman of ]\Iiinden as captain, he sailed from 

 Cassel on September 24, 1707, with his family. At Miinden 

 however the guild of boatmen asserted their privileges, 

 the magistrates pronounced the boat confiscated, and a 

 handsome offer of ransom was rejected. Papin pushed 

 forward despairingly for England ; only to find him- 

 self almost unknown and friendless. The old genera- 

 tion was fast passing away. For two or three years 

 he continued his mechanical inventions, and several 

 times applied through Sloane for a grant of money from 

 the Royal Society to aid him in his work, but in vain. 

 Misunderstanding and misery followed apace. The 

 inventions on which he relied for fame and position were 

 passed by unnoticed. In the loss of his ship he had 

 made shipwreck of his life's hopes. He died in London, 

 probably, in the early half of the year 17 12, but in such 

 obscurity that neither place nor date is with any cer- 

 tainty known. 



Dr. Gerland appears to have spared no pains in col- 

 lecting the scattered facts of Papin's life and work from 

 which to build the volume whose contents we have 

 endeavoured to make known to English readers. We 

 congratulate him on his success, and trust that his 

 effbrts will be further rewarded by the discovery of the 

 facts still required to fill the lacutiix in the career of this 

 remarkable man. The light which the publication of 

 the correspondence between Leibniz and Papin throws 

 upon the relation between two prominent figures amongst 

 men of science at that time is by no means the least inte- 

 resting feature of the work ; and we must henceforth place 



