516 PROCEEDINGS OF THE WASHINGTON MEETING 



His greatest piece of geologic work — that on the geolooj}^ of the Sierra 

 Nevada — has not yet been published. Begun about 1880 and continued 

 up to the time of his death, it illustrates well his views of how a man of 

 science should serve mankind. After some time spent in studying the 

 geolooy of the Sierra Nevada at various points, he became convinced that 

 the detailed study of a section across the mountains and embracing its 

 tj^pe formations ought to solve at once most of its geologic problems. 

 Such a piece of work, however, no business enterprise would think of 

 undertaking, for it could not be counted upon to yield financial results, 

 and no scientific institution felt able to undertake it. He therefore de- 

 termined to do the work unaided, and all the time and mone}^ he could 

 spare from other duties were thenceforth devoted to this investigation. 

 Topographers and field assistants were employed out of his private 

 funds, and an area of 160 square miles was mapped in great detail. 

 The field notes Avere plotted on a scale of 1 to 2,400 and afterwards re- 

 duced to 1 to 12,000. In addition to this, an area of about 800 square 

 miles was mapped on a mile to the inch scale. It should be remembered 

 that this area lies across the high Sierras, chiefly in a forest-covered 

 region that is very thinly populated and where field work is retarded 

 by late and early snows. 



A part of Mr Mills' results, obtained in his stud}^ of the sierras, are 

 published in volume 3 of the Bulletin of this Society ; but the bulk of 

 them was not yet in shape for publication when he died. He was look- 

 ing forward with pleasant anticipations to spending the last years of his 

 life in making this piece of work his greatest contribution to geologic 

 knowledge.* 



Mr Mills was an inspiring teacher, and he had the art, by the use of 

 simple and effective illustrations, of making things easy and at the same 

 time impressive. He was a warm and tolerant friend, but he was like- 

 wise a warm and uncompromising enemy. As a geologist, he endeav- 

 ored to be governed always by a judicial mind ; but when he believed a 

 thing he usually believed it ver}^ vigorousl3^ and this trait of character 

 sometimes led him into error and afterward caused) him deep regrets. 

 When he found himself in the wrong, however, he made haste to set 

 himself right. He was a man of broad s\anpathies and was deeply 

 interested in all kinds of social and economic questions. 



BIBLIOGKAPHY 



Manganese deposits in Virginia. Anier. Chemist, vol. 2, no. 2, August, 1871, pp. 

 49-51. New York. 



* Mr William Watson, of Quincy, California, has been Mr Mills' faithful assistant in all this 

 work in the Sierra Nevada. 



