20 



THE POPULAR SCIENCE MONTHLY. 



by M. de Navarrete, in the form of a letter from Tomas Gonzales, 

 Director of the Royal Archives at Simancas, Spain. 



9. In 1601 Giovanni Battista della Porta, in bis work "Spiritali," 

 described an apparatus by which the pressure of steam might be 

 made to raise a column of water, and the method of operation included 

 the application of the condensation of steam to the production of a 

 vacuum into which the water would flow. He used a separate boiler. 

 Fig. 3 is copied from an illustration in a later edition of his work. 1 



Fig. 3. Porta's Apparatus, a. b. 1601. 



10. In 1615 Salmon de Caus, who had been an engineer and archi- 

 tect under Louis XIII. of France, and later in the employ of the Brit- 

 ish Prince of Wales, published a work at Frankfort, entitled " Les 

 Raisons des Forces Mouvantes avec diverses machines tant utile que 

 plaisantes," in which he illustrated his proposition, " Water will, by 

 the aid of fire, mount higher than its level," by describing a machine 

 designed to raise water by the expanding power of steam. (See Fig. 4.) 



This consisted of a metal vessel partly filled with water, and in 

 which a pipe was fitted leading nearly to the bottom and open at the 

 top. 



Fire being applied, the steam, formed by its elastic force, drove 

 the water out through the vertical pipe, raising it to a height depend- 

 ing upon either the wish of the builder or the strength of the vessel. 



11. In 1629 Giovanni Branca, of Lovetto, an Italian town, de- 



1 " I Trc Libri Spiritali," Napoli, 1606. 



