6 The American Geoloyist. January, is97 
Hall and Mr. F. J. H. Merrill in their respective geological 
map? of the state. This statement, however, assumes that 
Mather would have accepted certain modifications ot" presen- 
tation, such as the use of the terms Cambrian for the primor- 
dial fauna and the acceptance of the belief that the Granular 
quartz of Emmons is not the equivalent of the Potsdam but a 
much lower horizon. 
Mather's name has been mentioned in connection witli the 
suggestion that the State Geologists should meet for consul- 
tation, and with their co-workers form an association of ge- 
ologists. In November 1838, not being able to be present, at 
the meeting, he addressed a letter to the New York board of 
geologists, presented through professor Emmons, commencing 
as follows : " Would it not be well to suggest the propriety 
of a meeting of the geologists and other scientific men of our 
country at some central point next fall, sa}'' in New York or 
Philadelphia. There are many questions in our geology that 
will receive nevv'^ light from friendly discussion and the com- 
bined observations from various individuals who have noted 
them in various parts of our country. Such a meeting has 
been suggested by professor Hitchcock and to me it seems 
desirable," etc. 
From a letter of Mather to Hitchcock in 1S49, it ai)peai's 
that professor Vanuxem made the motion before the Board 
to adopt the suggestion; and it is a well known fact in his- 
tory that this vote led to the formation of the "American Asso- 
ciation of Geologists,*' followed several years later by the 
American Association for the Advancement of Science.* 
The Geological Survey of Ohio was carried on during the 
years 1837 and 1838. Greater help was obtained from assis- 
tants than in the New York survey. As the result of these 
two years of labor Prof. Mather was enabled to establish the 
column of formations, whose accuracy was certified to b}^ the 
later works of Dr. J. S. Newberry. The basal rock is the 
"Blue limestone" or Lower Silurian, followed by the"Clilf 
limestone," which has been identified with the Upper Silurian 
*The correspondence relating to this subject is given in the Tenth 
Annual Report of the Regents of the University on the State Cabinet 
of Natural History, page 23. It seems that Hitchcock wrote on this 
subject to Mather in 1837 and 1838. 
