VOL. XIX.l PHILOSOPHICAL TRANSACTIONS. 155 



by means of some river not far distant from them. And this is performed by the 

 pressure of the air to ryhndrical vessels, being alternately evacuated, whose 

 plugs alternately descending again, turn a wheel, which raises two buckets that 

 discharge the water. 



The fourth letter shows a method of draining mines, where you have not the 

 conveniency of a near river to play the aforesaid engine: where having touched 

 on the inconveniency of making a vacuum in the cylinder for this purpose with 

 gunpowder, he proposes the alternately turning a small surface of water into 

 \apour, by fire applied to the bottom of the cylinder that contains it, which 

 vapour forces up the plug in the cylinder to a considerable height, and which 

 (as the vapour condenses as the water cools when taken from the fire) descends 

 again by the air's pressure, and is applied to raise the water out of the mine.* 



The fifth is concerning a dispute between M.D. Gulielmini and Mr. Papin, 

 concerning running water^, the decision of which he refers to M. Huygens. 



The sixth is an abridgment of a dispute between himself and the same person, 

 concerning the true estimate of powers or moving forces. 



Tlie seventh treats of instruments to conserve flame underwater, against th^ 

 objections of Mr. Scarlet. He ends with the description of a |)!unging-boat, 

 or parallepipide vessel made of tin, 5^ feet high, 5-i- long, and 21 broad, 

 strengthened with cross-bars of iron ; which vessel, by means of a pump (w.'jich 

 has communication with the external air above the water) is to be continually 

 supplied with fresh air, by drawing down the sucker of the pump. 



The whole treatise concludes with an harangue, which the author made when 

 he was admitted professor of mathematics at Marburgh. 



^ Letter from Dr. Charles Morley to Dr. Bernard Connor, F.R.S. giving an 

 Account of the Bones of a Foetus voided per Amim, some Years after Concep- 

 tion. An abridged Translation from the Latin. N°227,p. 486. 



In this letter it is stated that Mary Kid, about 30 years of age, who had borne 

 children before, and who lived at Swasy, became pn-gnant in the year ]658. 

 She grew large, and had all the symptoms common in such cases. Towards the 

 comjjletion of the usual period of gestation, she sent for a midwife, and was 

 seized with labour-pains; but no parturition ensued, and the pains ceased, 

 although the enlargement of the abdomen continued. Things remained in this 

 state for a year and a half afterwards. She then heard of a certain country 

 quack, to whom she applied ; and who undertook to cure her, not by medicine, 



* The principle of ilie steam-engine ; but much inferior in the contrivances to that described by 

 the Marquis of Worcester, in his Century of Inventions, published in l663. 



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