34 W. Upham—Minnesota Valley in the Ice Age. 
These elements correspond to a period of about 400,000 
ears. 
: Recomputing the position of the comet for the dates of the 
six normal places and comparing gives the following results, 
the column headed ‘‘v” being the residuals obtained by sub- 
stituting in the equations of condition the values found above 
for the unknown quantities. 
da cos 6 v v 
(C—O) (C—O) 
March 26.5 +1°36 +1°34 +1°01 +1°00 
April 12.3 — 0°86 —0°71 —1°31 —1°31 
May 25.5 +153 +1°52 +0°19 +017 
June 2.5 —0°61 — 0°60 +0°04 +0°03 
July 9.5 +0°37 +0°38 — 2°33 —2°16 
August 7.5 —0°91 —0°95 + 4°30 +4°24 
The planetary perturbations being small have not as yet 
been taken into account, as I intend to make a more complete 
discussion of the comet when all the observations have been 
published. 
Field Memorial Observatory, Williamstown, Mass. 
Art, VII.—The Minnesota Valley in the Ice Age;* by 
WarREN UPHAM. 
occupies a very remarkable valley, the origin of which was 
first explained in 1868 by General G, K. Warren, who attributed 
it to the outflow from an ancient lake that filled the basin of 
the Red River and Lake Winnipeg. This valley or channel 
begins at the northern part of Lake Traverse and first extends 
southwest to the head of this lake, thence southeast to Mankato, 
* Read August 16, 1883, at the Minneapolis meeting of the American Associa- 
tion for the Advancement of Science. 
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