Ox THE MECHANICAL EQUIVALENT OF HEAT 



409 



2. KESULTS OF BEST DETERMINATIONS ' 



On the basis of this table of methods I have arranged the following 

 table, showing the principal results so far obtained. 



In giving the indirect results, many persons have only measured one 

 of the transformations required; and as it would lengthen out the table 

 very much to give the complete calculation of the equivalent from these 

 selected two by two, I have sometimes given tables of these parts. As 

 the labor of looking up and reducing these is very great, it is very 

 possible that there have been some omissions. 



I have taken the table published by the Physical Society of Berlin, 1 as 

 the basis down to 1857, though many changes have been made even 

 within this limit. 



I shall now take up some of the principal methods, and discuss them 

 somewhat in detail. 



Method from Theory of Gases 



As the different constants used in this method have bf en obtained by 

 many observers, I first shall give their results. 



TABLE XXVII. SPECIFIC HEAT OF GASES. 



25 Taking mean results on page 101 of Rel. des Exp., torn, ii., 



