CONDITIONS AT INSPECTION OF TESTS 123 



From practical experience of the wearing of white lead and zinc 

 oxide, and the comparative hardness of these two pigments, 

 zinc oxide was selected as the maximum for hardness and termed 

 number 10, while white lead was selected as the minimum and 

 termed number 1. The varying degrees of hardness exhibited 

 by the formulas were recorded in terms from one to ten. This 

 comparison of course was only an approximate one. 



General Condition. The so-called general conditions of the 

 panels was, as a rule, the consensus of the judgment held by 

 the various inspectors, with due regard to such properties as 

 chalking, checking, gloss, hiding power, color maintenance, 

 condition of surface, etc. 



