Sketch of Dr. John Locke. — Winchell. 345 
tion, permit me to observe that I shall not charge the State of 
Ohio my salary during this excursion beyond its limits, but 
as a sketch of the information would, I thought, serve to show 
the connection of our geological formations with those of an 
adjacent state, I have taken the liberty of offering it to the 
service of our citizens." (p. 238). 
In this report he described and figured Isotelus maximus 
(which he afterward changed to Isotelus megistos), comparing 
it accurately with fsotelvs megalops Green. His specimen was 
21 inches long, its great size being the only definable differ- 
ence which he could discover between it and Green's /. mega- 
lops, which was 5 inches long. He feared his specimen might 
be "actually an overgrown megalops of Green." He made also 
a careful examination and illustration of certain peculiar "di- 
luvial grooves" which he found seven miles above Da} r ton, on 
the limestone of Light's quarry, in Montgomery county. He 
compares them with grooves described by Dr. Hitchcock on the 
Primitive rocks of Massachusetts, and suggests that they may 
be due to icebergs floating over the terrace. "The rectilinear 
course of these grooves corresponds with the motions of an im- 
mense body, the momentum of which does not allow it to 
change its course upon slight resistances." The glacier hy- 
pothesis of professor L. Agassiz had not then been heard of in 
America. 
The "first survey" of Ohio w r as discontinued because of the 
failure of the Legislature to make the necessary appropria- 
tions of nione}^ ; indeed, the second year's work, and the most 
valuable portion of the report published in 1838, resulted 
from the unexpended surplus of the funds appropriated for 
1837. The survey was well begun and ably maintained, but 
its utility was not appreciated. 
The following year (1839) Dr. Locke was in the service of 
the United States government under Dr. I). 1). Owen in the 
survey of the "Mineral' Lands of the United States." It shows 
how little conception of the mineral wealth of the United 
States the government then entertained, to observe that such 
lands were defined as "all the lands in the Mineral Point and 
Galena districts which are situated smith of the Wisconsin 
and north of the Hock river, and west of the line dividing 
ranges eight and nine east of the fourth principal meridian, 
