1868.] 151 [StocMcr. 



scratching!;?, Avhich would delight the eye of one determined to see 

 only the agency of moving ice in such records, are often to be seen 

 in the actual process of formation in a tempei'ature some 30° above 

 the freezing point. 



Mr. S. H. Scudder observed that even the comparatively few bould- 

 ers which Mr. Shaler admitted to emerge from beneath the glacier at 

 the terminal moraine, were really so numerous that they ought not to 

 escape the eye of the careful observer; and that so vast a body of 

 ice as this theory rendered necessary — however slowly it might 

 move — would, by its own weight, irrespective of any enclosed masses 

 of rock or gravel, polish and round the surface over which it passed. 



Section of Microscopy. Noverabei- 11, 1868. 



Dr. B. Joy Jeffries in the chair. Six members present. 



Mr. Charles Stodder laid upon the table, for tlie inspection 

 of tlie members, photographs of Robert's test plate of nine- 

 teen bands, taken by Dr. Curtis, under directions from Dr. 

 Woodwai'd, at the Army Medical Museum in Washington, 

 D. C. 



These bands are very beautifully photographed, showing up to the 

 sixteenth perfect lines that can be counted through the whole width. 

 Their instruments failing to resolve, or rather to photograph the four 

 finer bands, sixteen, seventeen, eighteen and nineteen. Dr. Wood- 

 ward infers that the last four bands have not been resohed. 



Mr. Stodder remarked that in his opinion the claim to have I'e- 

 solved the finer bands, advanced by Mr. Greenleaf and himself, was 

 not disproved by this failure to photograph them. The condition of 

 the microscope for photogra^ahing (without an eye piece) is so diifer- 

 ent from its condition for vision, that he considered the failure to 

 photogra])h hues of such exceeding delicacy no proof that the lines 

 could not have been seen, and more than that, that the failure of one 

 operator to jihotograph with a certain instrument, is not to be ac- 

 <:epted as a proof that another observer with another instrument and 

 other manipulations failed to see. This subject Avas further discussed 

 by Drs. Jeffries and Curtis. 



