Septembee 27, 1895.] 



SCIENCE. 



401 



which lie off the coast of Maine and New 

 Hampshire. Statements made by reliable 

 residents seem to show that some of the is- 

 lands have risen six feet in the last fifty 

 years, while the rest seem to be stationary. 

 The general rock is gneissoid to schistose 

 and varies in color from white to black. 

 The islands are traversed by numerous 

 dykes of basic rock. On Appledore Island 

 there is a peculiar six-sided column of 

 granitoid rock protruding through a schis- 

 tose, biotite gneiss. The column is more 

 than eleven feet in diameter and its original 

 height must have been from 25 to 50 feet. 



' The Great Falls of the Mohawk at 

 Cohoes, N. Y.,' by W. H. C. Pynchon, 

 Trinity College, Hartford, Conn. This paper 

 described, by the aid of maps and stereop- 

 ticon views, the gorge of the Mohawk and 

 the falls. The author brought out the fact 

 that the rocks, which are Hudson river 

 shales, dip sharply down stream instead of 

 up stream as is the case at many falls, 

 notably Niagara. The gorge is shown to 

 be a post-glacial cutting and the old valley 

 still exists not far from the present one. The 

 position of the strata facilitates the forma- 

 tion of innumerable pot holes of all sizes 

 up to ten feet in diameter. 



In a paper entitled ' Subdivisions of the 

 Upper Silurian in Northeastern Iowa,' A. 

 G. Wilson, of Hopkinton, la., gave litho- 

 logical and palteontological characteristics 

 on which he would propose to divide the 

 Niagara strata there into five groups : 



5. The building stone. 



4. The upper coralline beds. 



3. The Pentamerus beds. 



2. The lower coralline beds. 



1. The beds of passage from the Maquo- 

 keta shales. 



Professor J. P. Smith, Stanford Univer- 

 sity, California, in a paper on the meta- 

 morphic series of the Shasta region of Cali- 

 fornia, supplemented observations which 

 the author detailed to the section at the 



Brooklyn meeting. New finds in the Mid- 

 dle Trias shales make the age assigned to 

 them more probable; certain strata which 

 are of Upper Trias combine in the same 

 beds fossils which are always in separate 

 beds in the Alps and Himalayas. The dis- 

 covery of an upper Karnic, or more proba- 

 bly Jurassic, fauna was announced. 



In the absence of the author, Mr. Warren 

 Upham's paper on a ' View of the Ice Age 

 as Two Epochs, the Glacial and the Cham- 

 plain,' was read in abstract at the request of 

 some members of the section. The author 

 divides the Glacial epoch of ice accumula- 

 tion into four stages : 1, Culmination of the 

 Lafayette epeirogenic uplift ; 2, the Kansan 

 stage, marking the farthest extent of the 

 ice sheet ; 3, the Helvetian or Aftonian 

 stage, during which there was considerable 

 recession of the ice- front ; 4, the lowan stage 

 of renewed ice accumulation. The Cham- 

 plain epoch of ice departure is divided into 

 four more stages continuing the others : 5, 

 the Champlain subsidence or Neudeckian 

 stage — a time of widespread depression ; 6, 

 the Wisconsin stage — marked by moderate 

 re-elevation of the land ; 7, the Warren, 

 stage, of maximum extent of glacial Lake 

 Warren, and 8, the Toronto stage, with 

 slight glacial oscillations, but temperate cli- 

 mate at Toronto and Scarboro,' Ontario. 



' A re-survey of the whii-lpool and vicin- 

 ity of the Niagai'a river, with a demonstra- 

 tion of the true geology of the locality, il- 

 lustrated by a new, large map.' In this 

 paper Mr. George W. Holley presented 

 some views regarding the origin and history 

 of the gorge of the Niagara which were 

 considerably at variance with those com- 

 monly accepted. by geologists. 



' Glacial phenomena between Lake Cham- 

 plain, Lake George and the Hudson ' was 

 the title of a paper by Professor G. F. 

 Wright, of Oberlin, Ohio, in which the au- 

 thor detailed the results of recent personal 

 study of that region. He described the mo- 



