62 Transactions of the American Institute. 



discoverer of the steam engine. When administering to him what 

 she doubtless thought %Yas a well deserved rebuke, little did 

 she understand the thoughts moving in that great brain and little 

 frame ; for Watt, you must recollect, was a puny child, with a 

 physical development which gave no promise whatever of his great 

 intellectual capacity and wonderful achievements. Little did he 

 dream that in those studies of the philosophy of the tea-kettle in 

 which he was then so intently engaged, was wound up, as the butterfly 

 in his cocoon, the embryo of the greatest discovery of modern times. 

 Let us then enter more in detail to the consideration of the arts 

 brought to light within the 100 years which have elapsed ; for you 

 must remember that January, 1869, will be exactly a century sinc« 

 the time of the contract between James Watt and Boulton of Soho, 

 by which one undertook to furnish the brains and the other the 

 capital, and which resulted in the introduction of the steam engines 

 into general use. [Prof. Silliman here illustrated this branch of his 

 subject by showing the effect of the Bunsen gas-burner in producing 

 heat and vapor. He explained why it was necessary to apply heat 

 to the bottom of a vessel to heat water to the boiling point ; that 

 where heat was so applied it produced an upward current through 

 the whole water. Heat applied to the top of the water would not 

 make it boil. After some remarks upon the phenomenon of heat, 

 while the water in the vessel was gradually rising in temperature, he 

 said : This vessel which we are heating has now become filled with 

 bubbles. Fishes breathe water because it contains atmospheric air, 

 while it is richer in oxygen than common air. The first phenomenon 

 therefore in seeing that kettle boil is the displacement of the air. 

 Tasting water that has been boiled, after the air has been expelled, 

 and before the air has time to return, it is flat and unpalatable. The 

 tea-kettle is boiling under the pressure of the atmosphere. Every 

 individual carries a ton weight in the pressure of the atmosphere 

 upon his person. Ordinarily we do not feel it ; but in walking on 

 the surface of miry clay we feel it, because then the upward pressure 

 on the soles of our feet is removed. The second condition we have 

 to consider, then, in the boiling in the tea-kettle, is that we are 

 boiling the water under the pressure of fifteen pounds to the square 

 inch. Boiling is not always necessarily connected with temperature. 

 If the pressure of the atmosphere is taken off, in whole or in part, 

 there may be ebullition without great heat. [Water at 120 deg. was 

 here boiled in the air pumps.] Boiling consists simply of little 



