454 



\GIENGE. 



[N. S. Vol. IX. No. 221. 



The formal meeting was followed by refresh- 

 ments and a social gathering, which lasted until 

 a relatively late hour. 



RiCHAED E. Dodge, 



Recording Secretary. 



THE PHILOSOPHICAL SOCIETY OF AVASHINGTON. 



The 497th meeting of the Society was held 

 on March 4th, at 8 p. m., in the assembly room 

 of the Cosmos Club. The first paper was by 

 Professor F. H. Bigelow on 'The Influence of 

 Electricity on Vegetation.' It was stated that 

 vegetation under the Aurora belt shows re- 

 markable developments, due not to the length 

 of the summer day, but to the electric cur- 

 rents. Experiments indicate that static elec- 

 tricity, supplied by machines, when applied to 

 plants increases their growth about 40 per 

 cent. Extensive trials in many places and 

 under different conditions generally confirmed 

 this result. 



The second paper was by Surgeon-General 

 Sternberg on ' Some Sanitary Lessons of the 

 Late War.' An abstract of this very interest- 

 ing and instructive address has not yet come to 

 hand. E. D. Peeston, 



Secretary. 



GEOLOGICAL SOCIETY OF WASHINGTON. 



At the 89th meeting of this Society, held in 

 Washington, D.C., on March 8, 1899, Mr. Ar- 

 nold Hague, U. S. Geological Survey, exhibited 

 a geological relief map of the Yellowstone Park 

 and of the Absaroka Range, in northwestern 

 Wyoming, showing some of the physical fea- 

 tures of the latter region by means of lantern 

 illustrations. The map is constructed on the 

 scale of one mile to an inch, the area represented 

 being approximately 75 miles square. The 

 base of the model is taken at 5,000 feet above 

 sea level, from which rise several dominating 

 peaks showing elevations of over 12,000 feet 

 above sea level. It requires about forty dis- 

 tinct colors to represent the different geological 

 formations into which the sedimentary and ig- 

 neous rocks have been divided. All the geysers 

 and hot springs areas are delineated, together 

 with the regions of extinct hydro-thermal ac- 

 tion. In the model a sharp contrast between 

 the rhyolite plateau of Yellowstone Park of 



Pliocene age and that of the eroded and dis- 

 sected plateau of the Absarokas of Miocene age 

 is clearly brought out. Mr. Hague stated that 

 he hoped the map would be sent to the Paris 

 Exposition next year. The lantern slides were 

 selected to illustrate the manner in which the 

 Absarokas were built up by the gradual accu- 

 mulation of breccias, agglomerates and basalt 

 flows, forced upwards from numerous fissures 

 and vents during a long period of time, and the 

 elevation of the range by the intrusion of pow- 

 erful stocks of gabbro, syenite, diorite, diorite- 

 porphyry and granite-porphyry. The character 

 of the diiferent breccias, the incisive trenching 

 of the deep canyons, and the stocks, together 

 with their associated sheets and network of 

 dikes, were discussed. 



Mr. F. B. Weeks, U. S. Geological Survey, 

 gave some observations made last summer in 

 the course of a reconnaissance in Jackson 

 Basin, northwest Wyoming. 



The Jackson Basin, he said, occupies a de- 

 pression within the Rocky Mountains, of Wy- 

 oming, of 5 to 8 miles in width and 45 miles in 

 length. The Teton range forms a lofty, pre- 

 cipitous barrier along its western side. The 

 valley has an elevation of 6,200 to 6,800 feet, 

 and the Tetons rise 7,000 feet above it. The 

 Tetons are noted for their wonderful Alpine 

 scenery. Jackson Lake and several smaller 

 lakes occur within the valley — all of glacial 

 origin. The northeastern portion of the basin 

 is covered with numerous morainal ridges and 

 hillocks. The eastern side is buried beneath a 

 great mass of material brought down by glacial 

 streams. They have the forms of huge deltas, 

 spreading out from the foothills in fan-shaped 

 areas, several miles long and as many miles in 

 width where they reach the Snake River. 

 Along some of the main streams terracing has 

 been well developed. The streams flowing 

 over these deltas follow well defined courses, 

 but have a tendency to spread laterally instead 

 of widening and deepening their beds. The 

 Upper and Lower Gros Ventre buttes are prom- 

 inent outliers of the Gros Ventre range. They 

 are formed, in large part, of Paleozoic rocks, 

 and are probably directly connected with the 

 main range. The heavy mantle of debris makes 

 it impossible to trace a definite connection. 



