316 



a length of 60 millimetres by 10 millimetres of diameter. We 

 therefore devised a process to determine with accuracy the expansion 

 of such short bars. This, we believe, we have effected, as our appa- 

 ratus will easily indicate an expansion amounting to the 50,000th of 

 an inch, or about the 2000th part of a millimetre. 



Omitting the description of our apparatus and of the details of 

 our operations, which would be long for this abstract of our results, 

 we give here a Table of the general results obtained with the fol- 

 lowing metals : 



From the above observations we deduce the following Table of 

 coefficients of linear expansion from to 100: 



Cadmium (pure) 0-00332 



Lead (pure) .. .. .. .. 0-00301 



Tin (pure) 0-00273 



Aluminium (commercial) ... . . 0*00222 



Zinc, forged (pure) 0-00220 



Silver (pure) 0-00199 



Gold (pure) 0*00138 



Bismuth (pure) 0-00133 



Wrought iron 0-00119 



