16 STEAM ENGINE. 



visible to man, there may lie fields of creation which 

 sweep immeasurably along, and carry the impress of the 

 Almighty's hand to the remotest scenes of the universe; 

 the other suggests that within and beneath all that 

 minuteness which the aided eye of man has been able to 

 explore, there may lie a region of invisibles ; and that 

 could we draw aside the mysterious curtain which 

 shrouds it from our senses, we might there see a theatre 

 of as many wonders as astronomy has unfolded, a 

 universe within the compass of a point." * 



Every person competently acquainted with English 

 parochial customs, will be aware how long the force of 

 steam must have been known, as evinced in the use of 

 the village aeolipile, distinguished by the name of " Jack 

 of Hilton ;" yet this custom, though continued from 

 time immemorial, seems not to have suggested any use- 

 ful invention. While the Marquis of Worcester was a 

 state prisoner in the Tower,")- some food being preparing 

 on the fire of his apartment, the cover of the vessel being 

 tight, was, by the expansion of the steam, suddenly 

 forced off, and driven up the chimney. This led him to 

 a train of thought, in reference to the practical applica- 

 tion of steam as a first mover. The result of his specula- 

 tions obscurely exhibited in his " Century of Inventions" 

 successfully wrought out by Sir Samuel Moreland, 

 Newcomen and Cawley, Beighton, Boulton and Watt, 

 and others, has at length terminated in that noblest 

 example of mechanical ingenuity, as it now exists the 

 STEAM ENGINE. The whole operation of an engine of 

 this kind depends upon two principles, the develop- 

 ment of the elastic force of aqueous vapour by heat, and 

 its sudden precipitation through the agency of cold, 



Chalmers's Astronomical Discourses. f In the year 1663. 



