442 Memoir of James IVatt, Esq . F. R. S. 



structed, that went by the name of Newcomen's engme, which 

 continued to be in use for the draining of mines, from 1705, till 

 Mr. Watt's great improvement, of which we are going to speak. 



Savary associated himself with Crawley; and the alteration in- 

 troduced by the latter, and by Neucomen, who probably was the 

 working engineer, was, that Savary, like the Marquis of Worces- 

 ter, raised the water by the pressure of steam. Whereas, in New- 

 comen's engine, which thev constructed and sold, the steam was 

 only employed as the means of procuring a vacuum in a cylinder, 

 in which was a piston, which was pressed down by the weight of 

 the atmospheric air. The piston was attached to a lever or beam, 

 at the other end of which was a weight, that raised the pistoq as 

 soon as there was a fresh quantity of steam let into the cylinder, 

 under the piston.When the piston got to the top, a jet of cold water 

 was introduced, that condensed the steam, and again producing a 

 vacuum, the piston descended bv the pressure of the atmosphere. 



Much time was employed in contriving methods to open the 

 cocks necessary; and it was not till 1717 that the ingenious Mr. 

 Boughton produced a machine, where all the operations of turn- 

 ing the cocks were performed by the engine itself. 



Had there been any other power capable of draining deep mines, 

 so expensive and complicated was this engine, that probably it 

 would never have been brought into use ; but necessity obliged 

 the miners to persevere in employing it, and constant endeavours 

 were made to reduce the expenditure on consumption of fuel, 

 though without any further progress than constructing the boilers 

 and fire-places under them, in a manner to lose less of the heat. 



Mr. Watt was, by natural genius, an inventor, and, by his edu- 

 cation and research, led to seek for oeconomy and perfection in 

 the machine, not by trifling improvements, but by a great altera- 

 tion in its principle. 



The original inventor of the steam-engine undoubtedly laid the 

 foundation for ail the wonderful effects that are now produced by 

 that mighty a)achine ; but while it was merely employed for the 

 drawing of water from mines, it was of but little importance, com- 

 pared to what it is at the present day: and that change, from a 

 small degree of importance, to that of the very first-rate degree, 

 was exclusivel" almost the work of Mr. Watt- 



We must distinguish the steam-engine from all other machines, 

 whether for spinning thread, or rolling iron, &;c. as they are all, 

 without exception, however useful and ingenious, the means of 

 applying power; but the steam-engir.e creates the power that it 

 applies, and in that is different from all other human inventions*. 



♦Although seventy or a hundred horses may have a power equal to a large 

 ateam-engine, how could such a number be employed in giving mstio)^ to 

 one machine ? The impossibility of producing equal or simultaneous effort 

 to 80 great a number is obvious. The 



