362 Jlie Amefican Geologist. December, i898 
treat of the ice-sheet in Scotland, Sweden and Norway, 
measured probably 50,000 or 100,000 years. 
It is therefore right that the Acheulian men should be 
termed primitive. They had not learned how to use the 
Creator's gifts. The power of invention, ready to bestow do- 
minion and utilization of animate and inanimate nature, lay 
dormant and was scarcely beginning to awaken; but even then 
the men in the Somme valley were doubtless mentally and 
physically developed far nearer to ourselves than to the mist- 
covered morning and dim dawn of the earliest human diver- 
gence from an ancestral anthropoid species perhaps ten or 
twenty times more ancient. 
On leaving Abbeville, our journey continued through 
Boulogne, Calais. Dover, and Canterbury, to London. Again 
in that great city, a few days were spent in its libraries, muse- 
ums, parks, and in excursions to the outlying country. Then 
we embarked at Southampton, eighty days after o\\\: landing 
there; arrived in New York on August 27th; and, after visit- 
ing eastern friends, reached home in St. Paul on September 
9th, bringing memories, experience, and note-books of the 
summer of 1897, ^0"g planned for and happily completed. 
THE GREAT TERRACE OF THE COLUMBIA 
AND OTHER TOPOGRAPHIC FEATURES 
IN THE NEIGHBORHOOD OF LAKE 
CHELAN, WASHINGTON. 
By Israel C. Russell, Ann Arbor, Michigan. 
In an article by Mr. William L. Dawson, on "Glacial 
phenomena in Okanogan county, Washington," published in 
the October number of this journal, exceptions are taken to 
my measurement of the hight of the great terrace of the upper 
Columbia, and to certain conclusions based on my recon- 
noissance in central Washington in 1892. Having made a 
second journey through the Lake Chelan region during the 
past summer and obtained additional data in reference to its 
surface geology, I feel that I am gualified to reply to Mr. 
Dawson's criticisms, and to offer in return a few suggestions 
in reference to his interpretations of the history of some of 
