678 Ja Sy VUAGLILIVAALGSS 
language, or understanding, but to actual diversity in the facts 
themselves, which only wide and profound studies in compara- 
tive historical geology can reduce to a system. When, there- 
fore, we attempt to speak of geological events in their chrono- 
logical relations, the known truth can be expressed only by an 
elastic use of a universal scale whose divisions are few, and 
whose boundaries are not precise. 
HENRY SHALER WILLIAMS 
NEw HAVEN, CONN. 
October 28, 1898. 
