28 



SCIENCE. 



[N. S. Vol. XV. No. 366. 



The distribution of the sand is carried on 

 from two directions : from the west along the 

 south shore and from the north along the east 

 and west sides of the 'forearm' of the Cape. 

 The result is that the elbow tends to extend 

 farther into the ocean, and Massachusetts Bay 

 is a pocket steadily filling up with sand from 

 the north. With the great fall of the tide on 

 that coast, however, broad shoals are daily 

 offered to sun and wind and the dried sands 

 are constantly blown up on the highest 

 dunes of the Cape, viz., those near Barnstable. 

 There are ancient dunes along the coast, some- 

 times farther inland and even covered by for- 

 ests, whose aggregation may be attributed to 

 special violence of wind action at a remote 

 period. 



The most prominent results of the erosive 

 action of the wind-driven sand are those per- 

 taining to the general sculpture of headlands 

 and sununits of dunes, and the eating away of 

 the softer layers of gravel and sand of which 

 the bluffs along the east coast consist. The 

 fine example of such erosion at Truro was de- 

 scribed in detail and illustrated by means of a 

 photograph. The recession of the face of the 

 bluff here and everywhere from a vertical 

 plane clearly indicates that its principal 

 erosion is being constantly carried on by 

 aerial rather than by marine attack. On the 

 Cape, as elsewhere along our Atlantic coast, 

 it is a common error to attribute the ravages 

 on bluffs and dunes, noticed after a severe 

 storm, too much to the incursions of the sea. 

 A very large part of the damage has been done 

 by the violence of the wind, reinforced by vast 

 quantities of sand and spray lifted up and 

 hurled continuously for hours against all op- 

 posing objects. 



Other effects of the natural sand blast are 

 shovTn in the pitted surfaces of small bodies 

 strewn upon the beach, in the projecting hard 

 minerals of the beach pebbles and in the de- 

 polishing of exposed portions of bits of glass 

 and pottery. 'Faceted pebbles' are lacking 

 from the beaches, because there is too much 

 motion to permit of grinding anything to a 

 flat surface. The rapidity of the eroding ac- 

 tion tinder favorable circumstances is surpris- 

 ing. During the great gale of November 25, 



1899, one night sufficed to convert into ground- 

 glass the window panes in the exposed sides of 

 the life-saving station at Truro. No scratches 

 or grooves appear in these surfaces, such as 

 have been observed in the sand-fretted pebbles 

 of a desert, the conditions of sand erosion on 

 a beach tending to pit the surface rather than 

 to produce striae. 



The least obvious, but perhaps the most im- 

 portant, effect of this form of erosion is upon 

 the flying sand grains themselves by mutual 

 attrition, minute particles not being protected 

 from wear as they are when suspended in 

 water. By the splitting of particles from the 

 grains and their own final reduction to the 

 most minute size, the production of silt is con- 

 stantly in progress upon these windy beaches, 

 and it is regularly carried away in suspension 

 by every tide. 



The papers of the evening were discussed by 

 Professors J. J. Stevenson and R. E. Dodge 

 and Dr. A. "W. Grabau. 



In response to an invitation from the chair 

 Dr. W. S. Yeates, State geologist of Georgia, 

 gave some account of the history of the geolog- 

 ical survey of that State and a brief statement 

 about the work being carried on by the present 

 organization. Appreciative comments were 

 made by Professors J. ~F. Kemp and J. J. 

 Stevenson and Mr. G. F. Kunz. 



Edmund O. Hovey, 



Secretary. 



RESEARCH CLUB OF THE UNn'ERSITY OP 

 MICHIG.4N. 



At a meeting of the Research Club of the 

 University of Michigan, held November 7, 

 1901, the evening was taken up with the pres- 

 entation of papers by Professors Rolfe and 

 Novy. 



Professor Rolfe spoke on ' The Use of Ellip- 

 sis in the Explanation of Grammatical Phe- 

 nomena.' 



Dr. Novy gave an account of the investiga- 

 tions which Dr. Freer and he had carried on 

 during the past year. After reviewing the 

 work hitherto done concerning the action of 

 metals, such as gold and copper, upon bacteria, 

 it was pointed out that the explanation of this 



