354 WATT. 



opinion seems to be, that the historian had never read 

 the book he thus describes ; but being anxious to 

 relieve Charles I. from the blame of his Ambassador's 

 negotiation, which proved the source of much outcry 

 against the King, he states the low opinion which the 

 latter entertained of Worcester's judgment as a proof 

 that he never would authorise him to act in so delicate a 

 matter as religious concessions without the privity of the 

 Lord- Lieu tenant, and he is very ready to strengthen 

 this view by showing that the opinion was well founded. 

 Be this, however, as it may, the ignorance and error 

 is all on Hume's side, for the work is highly creditable 

 to its author's learning and ingenuity, and it un- 

 doubtedly contains a proof that he had made one step 

 in advance of Caus towards the use of steam-power. 

 His Sixty-eighth Invention is entitled " an admirable 

 and most forcible way to drive up water by fire." He 

 describes his having made a " constant fountain stream 

 of water, raised in the proportion of forty times the 

 quantity of that which he converted into steam ;" and 

 he states that the height to which he raised it was forty 

 feet, clearly showing that it was not on the principle 

 of the sucking-pump, which can only raise water 

 thirty-three feet. He expressly says that, while the 

 atmospheric pressure by which the sucking-pump acts 

 is limited in its operation, the force of steam which he 

 employed " hath no other boundary than the strength 

 of the vessel which contains it." Finally, he seems 

 to have used a cannon as his boiler, which indicates his 

 having tried the experiment on a large scale. The 

 great doubt expressed by M. Arago whether or not 

 Lord Worcester ever executed the design more or less 



