CAPTIVE MOLECULES 



no more fully than the others, as the use of his famous 

 engines " Beelzebub" and "Old Bess" in the estab- 

 lishment of Boulton and Watt amply testifies. It ap- 

 pears that Boulton had been an extensive manufacturer 

 of ornamental metal articles. To drive his machinery 

 at Soho he employed two large water wheels, twenty- 

 four feet in diameter and six feet wide. These sufficed 

 for his purpose under ordinary conditions, but in dry 

 weather from six to ten horses were required to aid in 

 driving the machinery. When Watt's perfected engine 

 was available, however, this was utilized to pump 

 water from the tail race back to the head race, that it 

 might be used over and over. "Old Bess" had a cylin- 

 der thirty-three inches in diameter with seven-foot 

 stroke, operating a pump twenty-four inches in diameter; 

 it therefore had remarkable efficiency as a pumping 

 apparatus. But of course it utilized, at best, only a 

 portion of the working energy contained in the steam; 

 and the water wheels in turn could utilize not more than 

 fifty per cent, of the store of energy which the pump 

 transferred to the water in raising it. Therefore, such 

 use of the steam engine involved a most wasteful ex- 

 penditure of energy. 



It was long, however, before the practical machinists 

 could be made to believe that the securing of direct 

 rotary power from the piston could be satisfactorily 

 accomplished. It was only after the introduction of 

 higher speed and heavier fly-wheels, together with im- 

 proved governors, that the speed of rotation was so 

 equalized as to meet satisfactorily the requirements of 

 the practical engineer, and ultimately to displace the 



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