MODERN THEORIES OF HEAT AND LIGHT 



being now one hundred and seven degrees Fahrenheit. 

 . . . One hour and thirty minutes after the machinery 

 had been put in motion the heat of the water in the 

 box was one hundred and forty-two degrees. At the 

 end of two hours ... it was raised to one hundred 

 and seventy-eight degrees; and at two hours and 

 thirty minutes it actually boiled! 



"It would be difficult to describe the surprise and 

 astonishment expressed in the countenances of the by- 

 standers on seeing so large a quantity of cold water 

 heated, and actually made to boil, without any fire. 

 Though there was, in fact, nothing that could justly be 

 considered as a surprise in this event, yet I acknowl- 

 edge fairly that it afforded me a degree of childish 

 pleasure which, were I ambitious of the reputation of 

 a grave philosopher, I ought most certainly rather to 

 hide than to discover. ..." 



Having thus dwelt in detail on these experiments, 

 Rumford comes now to the all-important discussion as 

 to the significance of them the subject that had been 

 the source of so much speculation among the philoso- 

 phers the question as to what heat really is, and if 

 there really is any such thing (as many believed) as an 

 igneous fluid, or a something called caloric. 



" From whence came this heat which was continually 

 given off in this manner, in the foregoing experiments ?" 

 asks Rumford. "Was it furnished by the small par- 

 ticles of metal detached from the larger solid masses 

 on their being rubbed together ? This, as we have al- 

 ready seen, could not possibly have been the case. 



" Was it furnished by the air? This could not have 

 been the case; for, in three of the experiments, the 



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