REASON OF MOVING FORCES. 377 



Well, I must ask, should we dare to refuse the epithet of 

 invention to a proceeding at which the immortal author 

 of the earliest and true principles of statics and hydro 

 statics would have been astonished ? The apparatus of 

 Solomon de Caus, that metallic envelop in which an 

 almost indefinite motive power is created by the aid of a 

 fagot and a match, will always figure nobly in the his 

 tory of the steam-engine.* 



It is very doubtful whether Solomon de Caus, or Wor 

 cester ever had their apparatus made. This honour be 

 longs to an Englishman,! to Captain Savery.J I compare 



* It has been printed that G. B. Porta had given in his Spiritali, in 

 1606, nine or ten years before the publication of Solomon de Caus s 

 work, the description of a machine intended to raise water by means 

 of the elastic power of steam. I have elsewhere shown that the learned 

 Neapolitan does not speak, either directly or indirectly, of a machine in 

 the passage alluded to; that his aim, that his only aim, was to deter 

 mine experimentally the relative volumes of water and of steam; that 

 in the small physical apparatus employed for this purpose, according 

 to the very words of the author, the steam could not raise the water 

 more than a few centimetres (some inches) ; that in the whole descrip 

 tion of the experiment, there is not a single word implying the idea 

 that Porta knew the power of this agent, and the possibility of apply 

 ing it to the pi*oduction of a useful machine. 



Is it thought that I ought to have quoted Porta, at least- on account 

 of his researches on the transformation of water into steam ? But I 

 should then say that the phenomenon had already been studied with 

 attention by Professor Besson of Orleans, about the middle of the six 

 teenth century, and that one of the treatises of that mechanic in 1569, 

 contains a special essay on determining the relative volumes of water 

 and steam. 



f Bonnain says that, after Kircher s death, a model was found in his 

 museum of a machine which that enthusiastic writer had described in 

 1656, and which differed from that of Solomon de Caus only in one re 

 spectthe motive steam was engendered in a vessel totally distinct 

 from that containing the water to be elevated. 



t Thomas Savery was a sailor, but, not being in the Royal Navy, is 

 styled Esquire Savery in the Royal Society correspondence. Nor is 

 our author quite right in supposing this was the first engine. The 



