192 GROVE KARL GILBERT— DAVIS [UEil(naa [Yol!xxi, 



How much more interesting history would he if it included all the little personal items that 

 ought not to be publicly told as well as those that ought to be! If further evidence in support 

 of that generalization is wanted, let another passage be quoted from the above letter, which 

 shows that, genuine as Gilbert's pleasure surely was when the Geological Society elected him 

 to its presidency, he was glad to relinquish the office after faithfully filling it. "A presidency," 

 he said, "is one of the things for which one is twice glad. I am rejoicing just now that my 

 term of office has expired in two societies." The other one was the Philosophical Society of 

 Washington, to which reference has already been made. He was evidently not of the kind of 

 officer who not only holds office but holds on to office. 



Gilbert spoke on "Chemical equivalence of crystalline and sedimentary rocks" at the 

 Boston meeting of the Geological Society in 1893; and on "Sedimentary measurement of 

 Cretaceous time" and "Lake basins created by wind erosion" at the Baltimore meeting of 

 1894, the last two topics having been suggested by his field work in Colorado. The first of 

 the two was also presented before the Philosophical Society of Washington, in connection 

 with which a note upon it has been given above. The second was one of the many smaller 

 subjects to which Gilbert so often gave illuminating attention. Three kinds of lakes were 

 found on the plains: Those of one kind occupy hollows in deposits of glacial drift; those of 

 the second are barred by sand dunes; those of the third appear to occupy basins excavated 

 by the wind. These lakes "are so shallow that one may wade across them in any direction. 

 They have no outlet and no persistent inlets. Their catchment basins are small. Ordinarily 

 their basins interrupt divides between stream valleys, and they often rest upon the highest 

 tables of their vicinity. They are not permanent, but appear and disappear as storm and 

 drought alternately prevail. Some basins are ordinarily dry, holding water only for a few 

 days or weeks after a thunderstorm. The lakes of others are apparently perpetual, disap- 

 pearing only after a succession of dry seasons." 10 Of all the features noted in this concise 

 induction, the location of the lakes near the divides where water action must be weakest appears 

 to be most conclusive in pointing to the origin of their basins by wind action. 



At the Washington meeting of December, 1896, report was made on "Old tracks of Erian 

 waters in western New York," a subject in which he had made some remarkable discoveries 

 during the preceding half year, as will be told in a later chapter on Niagara, which will also 

 refer to a paper on " Glacial sculpture in western New York," presented at the December meet- 

 ing in New York City in December, 1898. A year later in Washington he described a sub- 

 merged forest in the valley of the Columbia River, which he had examined during return from 

 the Harriman expedition to Alaska. It thus appears that the Geological Society of America 

 admirably served its purpose, not only in the scientific way of promoting the early announce- 

 ment of original studies by its members, but also in the personal way of bringing together 

 its members, old and young, so that they should come to know each other. Gilbert in particular 

 was one of the seniors whose presence gave as much pleasure and profit to the juniors as his 

 precepts. 



THE NATIONAL ACADEMY OF SCIENCES 



The spring meetings of the National Academy of Sciences usually found Gilbert in attend- 

 ance, but he spoke rarely. A paper on "An American maar," giving an account of Coon 

 Butte, was announced for April, 1892, but this subject was treated much more fully before 

 the Geological Society of Washington at the end of the same year. He seldom attended the 

 autumn meetings of the academy in other cities, but an exception was made in favor of Balti- 

 more in 1892, when he spoke on the "Evolution of the moon," this subject also receiving much 

 fuller treatment in the Philosophical Society of Washington, as noted above. The only other 

 part that he took in the academy's activities was to present by title at the spring meeting of 

 1897 a memoir of G. H. Cook, State geologist of New Jersey. From that memoir, an earlier 

 number in the series to which the present memoir belongs, a passage may be disinterred for 

 reinterment here, a passage that is peculiar not only in the care taken to define a group of 



w Journ. Oeol., iii, 1895, 47-49. 



