SEA-FLSHERIKS LABORATORY. 



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in which d 2 is from 80 to 84 % of T ; 10 in which d 2 is 84 to 

 88 % of T, and so on. So also with the 3-ringed scales and 

 the higher groups. 



The d?s are thus not absolute measurements but relative 

 ones — being percentages of the Ts of each scale. 



Fig. 1. Diagram of a 2-ringed scale. 



