academy of sciences] SCIENTIFIC RELATIONS 137 



at its later meetings until 1885, when he acted as secretary of section E, geology and geography, 

 at Indianapolis, gave an account of the old shore line of Lake Ontario, and reported the sectional 

 proceedings anonymously in Science. He attended the Buffalo meeting of the Association the 

 next year, and spoke on " Niagara Falls as a time measure," a subject which he afterward devel- 

 oped in a remarkable measure, as will be told below ; it may be noted that in an anonymous report 

 in Science of that year (viii, 1886, 205) he was misrepresented as giving a more definite age for 

 the faUs than he intended. In 1887 he was chairman of section E at the New York meeting 

 of the association, and read an address on the work of the International Congress of Geology 

 especially concerning the nomenclature of time periods, their stratigraphic subdivisions, and a 

 color scheme for their representation on geological maps; all these subjects having received 

 much consideration from him as Powell's leading scientific adviser in Washington, and the last 

 of them being treated in the New York address in much the same manner as in Powell's first 

 report as director of the survey, above alluded to. 



This address closed with such excellent counsel as to the duties and limitations of the 

 International Geological Congress, that it is here quoted: 



The proper function of the Congress is the establishment of common means of expressing the facts of geology. 

 It should not meddle with the facts themselves. It may regulate the art of the geologist, but it must not at- 

 tempt to regulate his science. Its proper field of work lies in the determination of questions of technology; 

 it is a trespasser if it undertakes the determination of questions of science. It may decree terms, but it must 

 not decree opinions. 



During one of the sessions of this meeting most of those present were well satisfied by a 

 pertinent parliamentary ruling of the chairman. In the course of a discussion in which Powell 

 had taken part, a member whose manner had only too frequently disturbed scientific gather- 

 ings replied to Powell directly, addressing him by name; he was promptly called to order by 

 Gilbert who, rapping on the table, said as sharply as he ever spoke: "The speaker will please 

 address the Chan"; and the disturbing member had at least the sense and the grace to accept 

 the reproof, saying at once to the chairman, "You are perfectly right, sir," and governing him- 

 self accordingly for the remainder of the debate. 



Although Powell as president of the association attended the meeting at Cleveland in 

 1888, Gilbert was held in Washington by administrative work. On the other hand, in the sum- 

 mer of 1889 Gilbert attended the meeting of the association at Toronto and performed the 

 difficult duty of reading for Powell, who was then the retiring president but who was unable to 

 be present on account of new duties in connection with irrigation and reclamation of western 

 lands, an address surcharged with Powellian mannerisms on the " Evolution of music from dance 

 to symphony." It must have been a curious experience for those of the audience who knew 

 Gdbert's own simple manner of presentation, to hear him repeating, as a means of giving emphasis 

 to principles with which he had no personal concern, the redundant series of exuberant, rhapsodic 

 assertions and the surfeit of quaintly phrased illustrations which, particularly in this address, 

 characterized his chief's extravagant style; but the real Gilbert and his exceptional capacity 

 in scientific exposition were manifested in a public lecture on a subject that was a favorite theme 

 of his own for the next 10 years, the history of Niagara River, which he was then interpreting in 

 a truly marvelous manner; this address is outlined in a later section. 



THE NATIONAL ACADEMY OF SCIENCES : DEFLECTION OF RIVERS 



Gilbert was elected a member of the National Academy of Sciences in 1883, at the age of 

 40 years, and was a frequent attendant at the spring meetings in Washington thereafter. His 

 first communication to the academy was made in 1884, and concerned the effect of the earth's 

 relation in deflecting river courses, 5 an old subject to which he contributed a helpful step not 

 previously noted, by showing that it is not the whole current of a river that will suffer deflec- 

 tion so much as the fastest or medial current; and that for rivers in the Northern Hemisphere 

 this current, already displaced by centrifugal force toward the concave banks of a meandering 

 stream, will be in consequence of the earth's rotation alternately a little more pressed against 



» The sufficiency of terrestrial rotation for the deflection of streams. Amer. Journ. Sci., xivii, 1884, 427-432. 



