January 17, 1902.] 



SCIENCE. 



89 



estimated rate of erosion the entire lake 

 would be filled in 400,000 years, whereas 

 it is not a quarter full, and probably not 

 one tenth full. The age of Lake Baikal is 

 peThaps 100,000 years or less. That this 

 region was formerly connected with the 

 sea is shown by the species of seal found 

 in Lake Baikal, which are also found in the 

 Caspian sea. Other evidence of recent 

 submergence followed by reelevation exists. 

 A period of increased precipitation caused 

 the freshening of all the waters of the 

 inland lakes of this region. 



Professor Scott discussed the importance 

 of ffiolean action in the formation of strati- 

 fied beds, referring to those of Santa Cruz 

 in Patagonia, in which vertebrate remains 

 have been found finely preserved. 



On Some Anticlinal Folds: T. C. Hopkins 



and JIaetin Smallwood, Syracuse, N. Y. 



Read by Pi'ofessor Hopldns. 



A number of unique folds occur in sev- 

 eral small and rather deep ra'sanes in the 

 vicinity of Meadville, Pa. They are of 

 limited extent both vertical and linear, and 

 so far as known occur only in the bottom 

 of the ravines. The relation of the folds 

 to certain land-slip terraces, suggests a cause 

 for these folds which are often asymmet- 

 rical. 



Professor I. C. White referred to similar 

 folds in other portions of Pennsjdvania. 

 He considered that gas formed below 

 found an opportunity to escape in the rel- 

 atively weak bottoms of canyons, causing an 

 upward pushing of the strata. Professor 

 Brigham mentioned the occurrence of sim- 

 ilar folds in western New York. Professor 

 Russell recalled folds, in the bottoms of 

 canyons in western Idaho, where the strata 

 are sharply arched. Land-slip terraces oc- 

 cur on both sides, there being thus no un- 

 equal pressure. He considered that the 

 doAvnward pressure of the wall rocl^s of the 

 canyons, and the relief of pressure in the 



bottom, caused the arching. Professor 

 Stevenson discussed other folds in Pennsyl- 

 vania. Mr. C. J. Sarle mentioned folds in 

 the Clinton beds at Rochester and other 

 localities. 



The following papers were then read by 

 the author: 



Distribution of the Internal Heat of the 

 Earth: T. C. Chamberlin, Chicago, 111. 



Has the Bate of Rotation of the Earth 



Changed Appreciably During Geological 



History? T. C. Chamberlin, Chicago, 



111. 



The papers were a discussion of the 

 mathematical and physical principles in- 

 volved, and the available experimental 

 data. The geological application to the 

 phenomena of volcanoes, mountain fold- 

 ings, etc., and to the great questions of 

 physical geology was discussed. 



In discussion some remarks were made 

 by Professor Coleman. 



The Society then adjourned until the 

 next day. 



The annual dinner was served at eight 

 o'clock at the Whitcomb House. President 

 Walcott occupied the head of the table, 

 which was graced by the presence of a 

 number of ladies. The after-dinner 

 speeches touched upon the future policy of 

 the Society and other topics, and con- 

 tributed largely to the enjoyment of the 

 dinner, which was voted one of the best 

 ever attended by those present. 



Third day, Thursday, January 2, 1902. 

 The Council met at 9 o'clock in Sibley 

 Hall. The meeting of the Society was 

 called to order at 10 o'clock, Vice-Presi- 

 dent Winchell in the chair. Professor 

 Clarke asked for a statement from the 

 secretary concerning the relation of the 

 Society to Section E of the American Asso- 

 ciation, especially in regard to next win- 

 ter's meeting in Washington. 



The following papers were read: 



