80 Scientific Intelligence. 



way calculated to mislead. Professor Torell corrects the above 

 view bv makin-r Greenland the great source; but to put Green- 

 land in' the above sentence would make it absurd, for no height of 

 ice in that land, so far to the northeast, could have determined 

 iti,}ith,-ist'i;ird movements over New England. I did not doubt 

 that the ice mass of the Canada water-shed, continued northward 

 or northeastward, in the direction of the region of greatest precipi- 

 tation, as the chief iee-ma.-s of the continent ; but only whether the 

 increase of height in that direction exceeded enough that on the 



t of the ice-surface on the water-shed would 

 t least 13,000 feet to have given it a slope 

 of even fifteen feet a mile to its discharge in the ocean south and 

 east of }^cw England and ten feet a mile to the ice-surface over 

 Mount Washington — the smallest pitch that seemed to he capable 

 of producing the southward and southeastward movement ; and 

 the adding of ten feet a mile to the height farther north, thus 

 increasing this already incredible altitude I allude to (ii, 328) 

 but with an improbable if. The region of greatest height to the 

 north of the water-shed I did not consider, because it was not 

 within the range of my subject— the source of the "New England 

 Glacier;" and I had no satisfactory facts as to I he present amount 

 it ion to the north, much less any data for judging of 

 the hvurometrie condition in the Glacial era. 



Iu 'this Journal for April, 1875 (ix, 312), in citin- facts from Dr. 

 Cell, in the Report of the Canada Geological Survey for 1873-4, I 

 observe that the facts from the vicinity of Lake Winnipeg show 

 that a line of greatest glacier height was continued from the ice- 

 summit on the Canada water-shed northward; but not necessarily 

 that the height northward " was as great as over the water-shed," 

 for " the greatest height would have been where there was the 

 greatest amount of precipitation, supposing the melting the same." 

 1 then explain the absence of the glacier from the central re-ions 

 of the continent (exclusive of the Rocky Mountains) by reference 

 to the small amount of precipitation (referring to Schott's Rain- 

 chart), and to the high degree of summer heat, thus making the 

 glacier, as I state, n ^n.-at ooa^tward ice-tua.-s. thinning out to the 

 westward; and the- Continental ice-, not an ice-cap, but, as I say 

 in a subsequent note (x, 385, 1875), an " ice-mantle thrown about 

 the pole and descending along the borders of the Continent, 

 especially the eastern." 



6. A monograph of A m> ,•;<;<,, Tributes; by A. W. Vogdes, 

 U. S. Army. 16 pp. Tampa, Florida.— This pamphlet is Part I 

 of Lieut. Vogdes' monograph. It is wholly bibliographical, giv- 

 ing th- u'cneral bibliography on the subject, from the first paper, 

 in 16»8, by Lhwyd,and then, references to the works or memoirs 

 that treat of the several species of the genera Asiiphns, Odo/tto- 

 phut-ii \c laspis . /■■ i <, /; . v , -,,, J; " . , t lhis, Agraulos, 

 Ptychoparia (Conocephalites), and Ceraurus. 



