590 



CATALOGUE. — HEAT, EXPANSION. 



Nich. 8. IV. 63. 



Speer's hydrometer has • scales, for diiferent tempera- 

 tures. 



On air thermometers. Gilb. XV. 57. 

 Soldner on Dalton's laws of expansion. Gilb. 



XVII. 44. 

 *Hope on the contraction of water by heat. 



Ed. tr. V. 379. 



Makes the maximum of density between 39. 5° and 

 40°. 

 Mushet-on the shrinkage of cast iron. Ph. 



M. XVIIl. 3. 



Spirit thermometers are very inconvenient for travelling ; 

 fliey are easily deranged by shaking, so that the tube re- 

 mains constantly full, and the bubble in the ball. 



Expansions of different Substances. - 



According to the Committee of the Royal Society, the 

 apparent expansion of mercury in glass is ^55 for each 

 degree of Fahrenheit : this may be considered as a sufficient 

 definition of those degrees for the present purpose, placing 

 the freezing point of pure water at 3s". Dalton asserts, 

 that all liquids expand with greater rapidity exactly in pro- 

 portion to the elevation of their temperature above their 

 respective freezing points, m.aking the whole expansions 

 as the squares of the real temperatures ; but this does not 

 appear to be by any means true of mercury, nor of alcohol, 

 accordmg to the comparison of thermometers made in 

 Hudson's Bay : nor is it exactly true even in the case of 

 water. It appears, however, that in solids as well as in 

 fluids, equal increments of heat produce somewhat greater 

 expansions as the temperature is higher. 



Wedgwood says, th«t ear&eBware made porous 

 by charcoal, expanded only \ as much as 

 when solid. 



Much less than glass. Rittenhouse. 



Roy. Ph. tr. 1785. He had before found a glasi 

 tube expand 4 times as much as a rod. 



Smeaton. Ph. tr. 1754. 



Deluc's mean. Ph. tr. 1778. 



Roy. The same glass as the tube. 



Roy, 1777. As glass. 



Borda. 



Berthoud. 



Smeaton. 



Roy. 



Lavoisier. 



Roy. 



Ph. tr. 1795. 428. 



Smeaton. 



Lavoisier. 



Troughton. Nich. IX. 



Smeaton. 



Musschenbroek. 



Musschenbroek. 



Borda. 



Smeaton. 



Musschenbroek. 



Musschenbroek. 



Smeaton. 



Musschenbroek. 



Ellicott, by comparison. 



Musschenbroek. 



Smeaton. 



Musschenbroek. 



Borda. 



If glass expanded equally, the expansion of brass at 90° would be about 07 parts for l", the mean 

 of the whole scale being 108 ; but if the inequality of the expansion of glass is so great, as 

 appears from De Luc's experiments, the expansion of brass, al 90°, can be but about fiO pa;ts 

 for !». 



5 



