388 



SCIENCE. 



[N.S. Vol. XXIII. No. 584. 



Kemp called the meeting to order in the large 

 lecture hall of the American Musexim of Nat- 

 ural History and presented the speaker of the 

 evening, Professor E. T. Hill, who gave an 

 illustrated lecture on the Repuhlic of Mexico, 

 its physical and economical aspects. 



Meeting of November 6, 1906. — Vice-Presi- 

 dent Hovey presiding. 



Professor J. F. Kemp read a paper on ' An 

 Interesting Discovery of Human Implements 

 in an Abandoned River Channel in Southern 

 Oregon,' which will be printed in Science. 



Professor J. J. Stevenson, under the title 

 of 'A Bit of Quaternary Geology,' described 

 a small area in northwestern Vermont. His 

 conclusions were that after withdrawal of the 

 ice, clay was deposited along the streams to 

 an altitude of about Y50 feet above tide; that 

 upon this sand, gravel and boulders accumu- 

 lated to a thickness of about 450 feet. He 

 traced the steps in reerosion of the channel 

 ways as shown by the successive terraces. The 

 area in question is the northward extension 

 of Professor C. H. Hitchcock's third basin of 

 Winooski Kiver as defined in the ' Geology of 

 Vermont.' 



The third paper of the evening was by Dr. 

 A. A. Julien, ' Notes on Glaciation of Man- 

 hattan Island.' The evidences of plucking 

 action of the continental glacier upon the 

 crystalline schists of the island consist partly 

 of jagged broken surfaces beneath the till, 

 with angular transported blocks in the mo- 

 raine to the southeast; and partly of rounded 

 but roughened hummocks, pitted apparently 

 by a modification of semilunar cavities, such 

 as have been discovered in perfect condition 

 on scored surfaces of our limestone. 



Channels and pipe-like troughs were also 

 described and attributed to the action of sub- 

 glacial running waters, probably once con- 

 nected with waterfalls through crevasses in 

 the great glacier. The allied feature of pot- 

 holes, found just beyond the limits of the 

 island, was then discussed, and another hy- 

 pothesis advanced to account for their forma- 

 tion. 



A sudden southward change in the direction 

 of the glacial furrows over the island, their 

 asymmetric form, and distinct southward 



curvature, were described as evidences of a 

 decided slope of the general surface toward 

 the south-southwest, at the time of its sub- 

 sidence during the glacial movement. A 

 topographical modification was also referred 

 to, through the undercutting of joint planes 

 facing the northeast. 



Dr. George F. Kunz stated that during the 

 spring of 1905 there had been shown to him 

 some precious garnet, pyrope, in rounded ir- 

 regular grains, transparent, measuring from 

 two to five millimeters in diameter. That 

 these had been found in the tunnel extension 

 of the New York subway, about 1,200 feet 

 south of Pier No. 1, North River, under New 

 York harbor, at a depth of 110 feet below the 

 bed of the bay. That upon visiting the local- 

 ity he found that the entire walls of the 

 tunnel had been covered with the iron arches, 

 and it was impossible to see the rocks them- 

 selves, but that upon the dump heap he found 

 a number of masses of serpentine weighing 

 from two to one hundred pounds each. The 

 serpentine was a rich yellow, a trifle darker 

 than that found at Montville, N. J. Cleav- 

 ages of feldspar nearly a foot long, black 

 tourmaline, almandite, garnet in grains and 

 in crystals were noted, but no peridotite itself 

 was seen. This was probably due to the fact 

 that nearly all the material taken from the 

 tunnel was removed by barges to the deep 

 ocean and dumped. Dr. Kunz stated that it 

 was most unfortunate that what was undoubt- 

 edly the evidence of a peridotite dike upon 

 New York island should have been lost. A 

 mass of the gneissoid wall, measuring six 

 feet by ten and nearly covered by rich stilbite 

 was noted. Mr. C. Wotherspoon, the engineer 

 in charge of the night work, was most cour- 

 teous in giving information and in collecting 

 specimens. 



Meeting of December i, 1905. — Vice-Presi- 

 dent Hovey in the chair. 



Dr. Kunz reported the death of Dr. Augus- 

 tus C. Hamlin, of Bangor, Me. Voted that 

 a committee be appointed to make a minute 

 of Dr. Hamlin's death. Dr. Kunz appointed. 



Dr. Geo. F. Kunz described the Modoc 

 meteorite that detonated over Modoc, Scott 

 County, Kansas, at 9 :30 p. m., September 2, 



