Saville.] 
586 
[April 16, 
moraine but include moraines of various ages. This is sh wn by 
the position of the Kettle moraine of Wisconsin, which, though 
one of the later moraines of the newer drift-sheet, is at the very 
border of the newer drift and in part of its course reaches even be- 
yond the older drift ; also by the overriding of moraines in the 
East White river lobe of Indiana and the Scioto lobe of Ohio. 
There are hypothetical reasons based upon altitude and amount 
of precipitation, in addition to conclusions drawn from the distribu- 
tion of the moraines east from the G-eorgian Bay and Lake Erie 
and from difference in surface erosion and other phenomena, which 
lead me to consider the outer portion of the newer drift of the east- 
ern United States to be newer than that of the interior. The 
fullest possible tracing and correlation of moraines is therefore 
necessary to determine the order of succession and relative age of 
sheets of drift in widely separated districts. Because two mo- 
raines hold the same relative position in separate series, it does not 
follow that they are of the same age. If the implement-bearing 
gravels at Loveland, Ohio, were derived from the outer moraine 
of the newer drift in that state, and the Trenton gravels from the 
outer moraine of the newer drift in New Jersey, it cannot be safely 
asserted that they are of the same age. The gravels at Trenton 
may be, for aught we know, as new as the gravels at Little Falls, 
Minnesota. 
The relation between certain silts in the Mississippi basin and 
on the Atlantic coast has not yet been ascertained. Those on the 
Atlantic coast have been included by Mr. McGee in the Quater- 
nary but are considered by him much older than the terminal mo- 
raine of New Jersey and Pennsylvania. Those in the interior are 
later than the older drift sheet. Implements have been found be- 
neath the silt both in the interior and on the coastal plain, and 
since these are among the oldest of discovered traces of man’s 
workmanship considerable importance attaches to the accurate 
determination of the age of the silts which overlie them. 
THE SANBORN BOWLDER. 
BY M. H. SAVILLE. 
Last November, in company with Dr. J. E. Sanborn, of Rock- 
port, and Mr. Warren Upham, I made a visit to a large granite 
