laa GREAT MEN OF SCIENCE 



the ice floating on the river, and this led also to the Land- 

 grave's losing interest for the affair. Pumps in which steam 

 acted directly upon the water had meanwhile come into use 

 in England. Even thirty-five years earlier (1663) a pump of 

 this kind had been constructed by Lord Somerset, Marquis 

 of Worcester, with the aid of the skilful mechanic Kaspar 

 Kalthoff in London, and excited great interest, so that 

 Lord Somerset composed a special prayer for himself in 

 order to preserve himself from excessive pride over his 

 success.^ 



After being forgotten for decades, no doubt for want of 

 sufficiently skilful construction, this invention was taken up 

 again by the Englishman Savery, who in the year 1698 (the 

 same year as Papin) described a new and improved form of 

 the pump, and showed it in 1699 as a model to the Royal 

 Society, and later to the King of England. Landgrave Carl 

 in Cassel heard of this and was thereby led to giving Papin, 

 in the year 1705, a fresh order to carry out a machine of this 

 kind. It was finished in 1706 and pumped water to a height 

 of 70 feet; but the pipe line, which was cemented together 

 from a number of pieces, did not remain watertight. The 

 Landgrave then had a pipe made of copper, but was con- 

 tinually hindered from attending to the matter, and no 

 experiments were allowed to be made without his presence. 

 Finally, in the year 1707, even the copper tube was taken 

 away from Papin, since it was destined for another purpose. 

 This and other similar misfortunes, finally led Papin to 

 carry out the plan he had always borne in mind, of again 

 seeking his fortune in England. He first published in the 

 same year an account of his water pumping machine in a 

 special pamphlet which he sent to Leibniz, whereupon the 

 latter communicated to him the idea of automatic operation 

 of the valves, thus enabling the person who had to work the 

 stopcocks to be dispensed with.^ 



^ See Poggendorff's History of Physics, 2 Correspondence, p. 375. 



