56 Mechanical Philosophy. [Chap. I. 



cies of navigation labours under difficulties which 

 appear at present insurmountable; though the 

 want of some means to control and regulate the 

 movements of the aerial vessel is so essential as to 

 excite a fear that it cannot be supplied ; yet who 

 can tell what further experience and discoveries 

 may produce ? Who can tell but another century 

 may give rise to such improvements, that navigat- 

 ing the air may be as safis, as easy, and rendered 

 subservient to as many practical purposes, as navi- 

 gating the ocean ? It must be acknowledged, in- 

 deed, that this is not very probable^ but things 

 more unexpected, and more remote from our habits 

 of thinking, have doubtless occurred. 



Under this head, also, properly come the great 

 improvements which have been lately made in 

 Steam Engines, doubtless among the most import- 

 ant and useful kinds of machinery that human 

 ingenuity ever contrived. The idea of making 

 steam subservient to powerful mechanical opera- 

 tions seems to have been first entertained by the 

 marquis of Worcester, in the reign of Charles II 

 of England. But little more was done, either by 

 him, or during his time, than to speculate on the 

 subject. It was not till the close of the seventeenth 

 century that captain Savary, an ingenious and 

 enterprising man, actually erected several steam 

 engines, and obtained a patent for what he consi- 

 dered his own invention. He afterwards improved 

 and simplified his machines himself; but the im- 

 provements which they have undergone since hi^ 

 time, are still more numerous. For these im- 

 provements the world is principally indebted to 

 Mr. Newcomen, Mr. Beighton, and above all to 



