44 



THE LINEAR COMPRESSIBILITY OF COPPER AND IRON, 



As in the case of the other substances, the jacket was first filled with 

 pure mercury, and a series of determinations was made of the pressures 

 needed to compress small successively added weighed globules of mercury 

 into precise contact with a finely pointed platinum wire in the narrow limb 

 of the jacket. This procedure was then repeated with pure water in the 

 jacket above the mercury, giving data previously detailed for the com- 

 pressibility of water; and finally once more with the solid metal and a 

 small amount of w^ater in the same jacket. The data concerning the first 

 two sets of determinations are given in the preceding paper; while the 

 last of the three series of data is given in the table below, with the results 

 calculated from them all together. The calculation is performed accord- 

 ing to the usual equation somewhat transposed, thus 



(WW G 0.2031 



5428 A 

 Determination of differences between compressibility of iron and copper and mercury. 



1 These determinations were made by W. N. Stull a year before the other work. Jacket in, described in the 

 preceding paper on non-metals, was used. 



The results are so concordant as to leave no doubt that the difference 

 between the compressibilities of mercury and copper is not far from 

 0.00000319, while the corresponding difference in the case of iron is about 

 0.000003325. The negative signs in the table indicate that each solid is 

 less compressible than mercury. 



