PROCEEDINGS. 
543 
342d Meeting. November 23, 18B9. 
President Eastman in the chair. 
Forty-two members psesent. 
Mr. George H. Eldridge read a paper on Certain Structural 
Features near Denver, Colorado. 
Published in this volume, pp. 247-274. 
Mr. J. S. Diller made a communication on The Sandstone 
Dikes of Northern California. 
Published in Bulletin of the Geological Society of America, 
8vo, Washington, April 1890, vol. 1, pp. 411-442. 
343d Meeting. December 7, 1889. 
Vice-President Dutton presided. 
About two hundred members and guests present. 
By courtesy of the trustees of the Columbian University, the 
meeting was held in the law lecture-room of the. University 
building. Members of the other scientific societies in Washing¬ 
ton and their friends were invited to be present. 
President Eastman delivered the annual address, entitled The 
Association of Assumption and Fact in the Theories of Solar and 
Stellar Proper Motions. 
Published in full in this volume, pp. 143-172. 
344th Meeting. December 21, 1889. 
NINETEENTH ANNUAL MEETING. 
President Eastman in the chair. 
Thirty-one members present. 
The chair announced the election to membership of Messrs. 
George Washington Littlehales and of John Fillmore Hay- 
ford. 
