708 PROFESSOR THOMSON ON THE ELECTRO-DYNAxMlC QUALITIES OF METALS. 
Explanation of Thermo-electric Diagram. 
The orders of the metals in the thermo-electric series, at different temperatures, are shown by the points in 
which the vertical lines marked with the temperatures Centigrade, are cut by the horizontal and inclined lines 
named for the different metallic specimens. 
Fig. 18. 
The object to be aimed at in perfecting a thermo-electric diagram, is to make the 
ordinates of the lines (which will in general be curves) corresponding to the different 
metallic specimens be exactly proportional to their thermo-electric differences * from 
a standard metal (P 3 in the actual diagram). 
§§ 102 , 103. Theoretical inferences regarding Electrical Convections of Heat, from 
facts of Thermo-electric Inversion. 
102 . The thermo-dynamic reasoning adduced above (§§ 10 to 15) leads to the 
conclusion 14, 15), that the convective power of the vitreous electricity is greater, 
or (which is the same thing) the convective power of the resinous electricity is less, in 
each metal for which the line in the diagram cuts the line for another metal from helow 
it on the left to above it on the right, than in this other metal. Now it was established 
* See “Dynamical Theory of Heat,” § 140. 
