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OUR PHYSICAL WORLD 



at one end of the cylinder while a valve at the other end was 

 open to let out the exhaust steam. Then these valves closed and 

 others opened to reverse the process. A second very important 

 improvement he thought out was the addition of condensing 



beam 



FIG. 71. Diagram of Watt's steam engine 



chambers. Instead of condensing the steam in the cylinder itself 

 the exhaust steam went to a separate chamber where it was 

 cooled by water. Since this chamber was a partial vacuum, the 

 exhaust steam rushed out of the cylinder into it the moment the 

 valve was opened so the pressure in one end of the cylinder was 

 very slight while that at the other was high because live steam 



