September 7, 18S3. 



SCIENCE. 



315 



formally: The condition of the state survey is likely 

 to be materially intlueuced by the law of the general 

 government extending the U. S. geological survey 

 over the states. Proper deference to the head of 

 the U. S. survey required that some action should 

 be taken by which we could confer with Major 

 Powell, to understand our relations to the survey. 

 To prevent any jealousy or uncertainty with regard 

 to what might be the relation of the state survey 

 and the general survey, I suggested the appointment 

 of this committee. I had no intention myself of 

 taking any active part in the matter; and I think 

 there are gentlemen on the committee, much younger 

 than myself, who will do all the work. I believe 

 several members of the committee have had very 

 pleasant interviews with Major Powell, as I have 

 myself, since these meetings commenced ; but I had 

 forgotten that I was to make a report. 1 think it is 

 desirable that there should be very frank intercourse 

 between the gentlemen who are conducting the st.ite 

 surveys and the head of the general government 

 survey, so that we may know what is to be the result 

 of their various surveys which are so very important 

 to geological science. Workers at a distance from 

 each other cannot, without some means of inter-com- 

 muuication, — which, I think, may be established 

 with the head of the general survey, — bring the 

 results of their labors to a fair comparison with those 

 which are done a thousand miles away. 



JIajor Powell expressed the hope that the commit- 

 tee would be continued. Several members of the 

 committee had conferred with him with reference to 

 the surveys, but Ihey had not conferred as a com- 

 mittee. Practical relations have been established 

 between the general survey of the United States and 

 several of the state surveys. He thought it was 

 probable that such arrangements could be established 

 as would make it satisfactory to all. 



The committee was continued. 



PAPERS READ BEFORE SECTION E. 



{PAPERS ON GLACIAL PUENOMENA.) 

 The life history of the ' Niagara river. 



BT JULIUS POI!LM.\N OF BUFFALO, N.Y. 



A SEKiES of observations whose points were given 

 in detail had convinced the author that the forma- 

 tion of the gorge of >fiagara had been a matter of 

 tens of thousands, rather than of hundreds of thou- 

 sands, of years. The beginning of the history miglit 

 be stated as in the pre-glacial epoch. A lake then 

 occupied the valley of the Tonawanda; its outlet 

 was the line of the ancient Niagara River from the 

 falls to the whirlpool: thence, by way of the St. 

 Davids valley, into the Ontario valley. All these val- 

 leys were closed during the glacial period. The sub- 

 sidence of Lakes Erie and Ontario was that of one 

 body or region, until they were separated by the 

 Lewiston escarpment; after that the drainage of 

 Lake Erie found its path through drift deposits 



and old existing valleys to Lake Ontario. The lat- 

 ter lake subsided slowly, and no waterfall was 

 formed at its entrance. The river excavated its 

 gorge to the whirlpool, not by means of a retreating 

 fall, but .as a rapid in an old shallow valley. At the 

 third pool, this patli met the ancient river-valley: it 

 was along that valley only, that the falls receded to 

 their present site. The retreat of the fall was not 

 the means of excavation, for at least seven miles 

 usu.ally ascribed to it ; the portion which would offer 

 the most resistance, between the falls and the whirl- 

 pool, being already excavated. 



From that point to Lewiston, the progress was 

 very rapid in cutting the gorge; a shallow valley had 

 partly removed the hard limestone, and the softer 

 underlying shale rock was a barrier much more 

 easily penetrated. We have no exact data of the 

 retrocession of the falls within periods of modem 

 observation. A comparison of Professor Hall's 

 map of the falls in 1S41, and that of the United- 

 States lake survey in 1875, shows wide discrepancies. 

 After all reasonable allowance for inaccuracies, we 

 must admit that parts of the Horse-shoe fall have re- 

 ceded in thirty-four years at least one hundred feet, 

 and on the American side the recession is from 

 twenty to forty feet. These f.acts all tend toward a 

 shortening of the history of the present river. 



In the discussion that followed. Professor Hall ex- 

 pressed a doubt as to the dependence that could be 

 placed on differences between surveys made by dif- 

 ferent persons, using differing methods. That there 

 had been retrocession within the period of our obser- 

 vation, he did not doubt; but it could scarcely be so 

 rapid as was Indicated by the estimates of Dr. Pohl- 

 man. Other speakers discussed the paper, which was 

 of special interest, because it fired the first gun of the 

 glacialists in the geological section, .^nd it roused their 

 opponents. 



Glacial cafions. 



BT W. J. McOBE OF SALT LAKE CITY, UTAH. 



Tuts paper was read, in the absence of its author, 

 by Mr. Warren Upham. It considered the action of 

 a glacier as being, to a certain extent, capable of 

 representation by mathematical formulae. It was 

 admitted, however, that some of the qu.intities in 

 the equations must remain very indefinite. The 

 paper was almost wholly theoretical, and .irrived at 

 the following conclusions : The temporary occupancy 

 of a typical water-cut cailon by glacier-ice w^ill, 1°. 

 increase its width; 2°. change the V to a U cross 

 profile; 3°. cut off the terminal portions of tributary 

 caQons, and thus relatively elevate their embouchures; 

 4°. intensify certain irregularities of gradient in the 

 cailon bottom: &°. excavate rock basins; (!°. develop 

 cirques; and, in general, transform each'cafion into an 

 cqu.ally typical glacial caiion. It follows that these 

 features do not necessarily imply extensive glacial 

 excavation, or indicate that glaciers are superlatively- 

 energetic engines of erosion. 



Owing to the custom of abstaining from discussion 

 on a paper in the absence of Its author, the dissen- 

 tient opinion of many who were present was not 



