30 PROCEEDINGS OF THE PHILADELPHIA MEETING 



geology of the Taconic and Archean rocks. A geological atlas forms 

 Volume VI, published in 1901, in which are reprinted all the map plates, 

 eighty-eight in number, of the preceding volumes, with brief descriptions 

 for each, written by Professor Winchell; and a general map is also pre- 

 sented, showing the approximate areas of the geologic systems below the 

 drift. 



My association with Prof. K. H. Winchell began in June, 1879. Com- 

 ing from the Geological Survey of New Hampshire, in which I had been 

 for several years an assistant, I was thenceforward one of the assistants 

 of the Minnesota Survey six years, until 1885, and again in 1893 and 

 1894. In the meantime and later, while I was an assistant geologist of 

 the surveys of the United States and Canada, on the exploration, map- 

 ping, and 2:>ubli cation of the Glacial Lake Agassiz, which occupied the 

 basin of the Eed liiver and of lakes Winnipeg and Manitoba, my frequent 

 association with Professor Winchell kept me constantly well acquainted 

 with the progress of his Minnesota work. Since the spring of 1906 he 

 had been in the service of the Minnesota Historical Society, having charge 

 of its Department of Archeology. During all these thirty-five years I 

 had intimately known him and had increasingly revered and loved him. 

 Besides being a skilled geologist, Newton Horace Winchell was a good 

 citizen, a Christian in faith and practice, beloved by all who knew him. 



Among the many special investigations which Prof. N. H. Winchell 

 published during the forty-five years of his active work as a scientist, 

 author, and editor, none probably has been more widely influential on 

 geologic thought and progress than his studies and estimates of the rate 

 of recession of the Falls of Saint Anthony, cutting the Mississippi Riv^r 

 gorge from Fort Snelling to the present site of the falls in Minneapolis. 

 This investigation, first published in 1876, gave about 8,000 years as the 

 time occupied by the gorge erosion, which is likewise the approximate 

 measure of the time that has passed since the closing stage of the Ice Age, 

 or Glacial period, when the border of the waning ice-sheet was melted 

 away on the area of Minnesota. 



Artificially chipped quartz fragments and rude aboriginal implements 

 found in the Mississippi Valley drift at Little Falls, in central Minnesota, 

 belonging to the time of final melting of the ice-sheet there, and other 

 traces of man's presence at nearly the same time, or even much earlier, 

 in numerous other localities of the southern part of our great North 

 American glaciated area, have led Professor Winchell and others, as the 

 late Hon. J. V. Brower, Professors G. F. Wright and F. W. Putnam, and 

 myself, to a confident belief that mankind occupied this continent during 

 the later part of the Ice Age, or even quite probably much earlier in that 



