Sir W. Scott on Oil-Gas. — Expansion ofGaseotcs Fluids. 469 



SIR WALTER SCOTT ON OIL-GAS. 



At a late Meeting of the Edinburgh Oil-Gas Company, 

 Sir Walter Scott said, that he had now had thi*ee months 

 experience of Oil Gas light in his house at Abbottsford, and 

 he could assure the Meeting that nothing could be more plea- 

 sant, more useful, safe, and economical. He was sure the 

 expense was not the twentieth part of what it had formerly 

 cost him for oil and candles. The light itself was greatly su- 

 perior, was extremely cleanly, saved much trouble to sei'vants, 

 and did not produce the least smell, or the least injury. Not 

 only could it be used in kitchens and dining-rooms, but it was 

 extremely useful in bed-rooms, where a flame could be kept 

 up durmg the whole night so minute as to be scarcely per- 

 ceptible, which could be enlarged to a powerful light in an 

 instant at any hour when wanted. It was also very safe ; at 

 least it was much safer than common lights, for it was not 

 carried from place to place as common lights were, and unless 

 combustibles were brought to it no danger could arise. The 

 light was indeed so convenient, cheap, and delightful, that were 

 it once introduced, he was convinced it would be used within 

 two years in every private house in Edinburgh. — Scotsman, 

 Nov. 29, 1823. 



EXPANSION OF GASEOUS FLUIDS. 



According to the experiments of Gay-Lussac, which have 

 been verified by Dulong and Petit, the expansion of air and 

 other gaseous fluids is nearly ^^^ part of the bulk for one de- 

 gree of heat, measured by Fahrenheit's scale, when the tem- 

 perature is not increased beyond 212°. But, according to 

 Dulong and Petit, the expansion is less in high temperatures. 

 Taking the expansion for the whole range from the freezing 

 point of water to the boiling point of mercury, the expansion 

 for each degree would be only ^i j, supposing it to be equable. 



If we consider the expansion to be equable, and make A the 

 bulk of the gas at the inferior temperature, and B its bulk 



when its heat is increased t degrees, and — the expansion for 

 one degree, we have a ^1 4-— ^ — R 



Ur, V-+ _ j5^ when the temperature is increased ; and 



— — = A, when the temperature is diminished. 



If e = 4'80, the formulae are 



jii|^ = B, when the temperature- "^ i'^^'eased ; nm\ 



480 B . , , at • ,i: -'"ished. 



—— = A, when the temiier ure is '' 



For 



