Januaey 20, 1899.] 



SCIENCE. 



113 



Bj' recession at the amphitheatre head — and 

 the glacier malvcs the amphitheatre, rather than 

 merely occupies it — the amphitheatral wall 

 is carried backward, and divides are cut through. 

 A summit region, upon either slope of which 

 glacial streams are extended, will be trenched 

 by streams heading thus in opposition. A iirst 

 effect of the meeting of an opposing pair will be 

 the arete, or thiu comb — the most evanescent of 

 mountain forms ; the final elFect will be the col 

 — a low-level pass between walls. The ulti- 

 mate result of continued glaciation must be 

 truncation of the crest region, close to the lower 

 level of the glacial generation. Transitional 

 forms will be not only the arete and the col, but 

 the aiguille, or minaret, the residual table, the 

 caiion of diverted discharge, the canon of 

 Yosemite type, and the towering peak of Mat- 

 terhorn type, against which divergent streams 

 will burrow at their heads, scalloping its base, 

 and maintaining its sinking summit as the sharp 

 apex of a slender and fluted pyramid. 



HARVARD UNIVERSITY : STUDENTS' GEOLOGICAL 

 CLUB, DECEMBER 19, 1898. 



Under the general title, ' Geological Results 

 of the Recent Storm upon the Massachusetts 

 Coast,' five members reported observations. 

 Mr. R. B. Earle described results noted on the 

 Winthrop and Beachmont shores. Winthrop 

 Beach, usually sandy and of gentle slope, bore 

 a series of gravel cusps, terminated on the sea- 

 ward side by spits that pointed toward^ the 

 southeast. Whenever these cusps were com- 

 posed of coarse gravel they were high and near 

 together ; when of fine material they were low 

 and far apart. In the Beachmont Bluff, at 

 similar intervals, was a series of cavern-like 

 undercuttings. A portion of the beach, be- 

 low the Bluff, was covered with heaps of sea- 

 weed shaped into cuspate forms, but another 

 portion was degraded to a depth of three feet. 



Mr. A. W. G. Wilson visited the south shore 

 from Windmill Point to Cohasset Harbor. At 

 the former locality sand and gravel were thrown 

 inland thirty feet. The railroad track that ran 

 close to high-tide level, along the front of the 

 drumlin upon which the town of Hull is located, 

 was protected by a breakwater of granite and 

 diorite blocks. From this breakwater, some 



blocks, which weigh approximately a ton or 

 more, were moved back ten feet and raised be- 

 tween one and two feet. Nantasket Beach, in 

 front of Strawberry Hill, was cut down four 

 feet, and back in places twenty feet, for a dis- 

 tance along the beach of five hundred yards. 

 Sections of sewer pipe thus revealed afforded a 

 basis for measurement. At the southern end of 

 Nantasket, where most of the wrecks were 

 washed up, large quantities of thoroughly 

 rounded, soft coal were imbedded in the beach 

 sand to a depth of at least ten inches. A short 

 distance east of Gun Rock, half a mile from Nan- 

 tasket, some houses stand one hundred yards 

 inland and from six to ten feet above normal 

 high water level. Coarse gravel accumulated 

 against these houses in heaps three feet high 

 and buried a neighboring road between two and 

 three feet deep. At Hull and in the region of 

 Gun Rock, where a salt marsh and a pond, i-e- 

 spectively, lay back of the beach, new, storm- 

 built beaches have encroached upon the marsh 

 and pond, in the form of well-marked series of 

 gravel spits from one to five feet in height. 



Mr. J. M. Boutwell offered three records of 

 height of water. At Lynn Beach the position 

 of pebbles and debris indicates the submergence 

 of its Nahant end. At its Lynn end, according 

 to the statement of an eye witness, the water 

 rose over the road to a depth of three feet and 

 swept completely across the beach. At Milton, 

 in the Neponset River, a rod has been so placed 

 that its top marks the height reached by the 

 high tide of 1851. One eye witness states that 

 during the recent storm the water rose to within 

 three inches of the top of this rod ; another 

 affirms that he saw it rise over the top. At the 

 Boston end of the West Boston bridge the 

 water in the Charles River rose to within one 

 inch of the street level. The tide predicted for 

 November 27th was the normal high-tide, ten 

 feet two inches at Boston. Had the storm 

 passed at the time of spring-tide, about two 

 days later, the water would have risen fully a 

 foot higher. As it was, the concomitant effect 

 of an imminent spring-tide, a strong, low pres- 

 sure area and an onshore wind was to raise the 

 water higher, at some points, than it was during 

 the high tide of 1851. J.M. Boutwell, 



Chairman. 



