160 



SCIENCE. 



[N. S. Vol. V. No. 108. 



minimum at an angle of 180°, when the collec- 

 tor is in a trailing position. The sum of the 

 coefficients for the two positions of maximum 

 compression and minimum exhaust is almost 

 exactly the same as Langley obtained with a 

 pressure board when exposed normally to the 

 wind. 



The result shows that a large amount of air 

 is dragged along with the train, the motion 

 being communicated to air many feet away. 

 This air is a source of danger to one standing 

 too near the train when at full speed. One is 

 likely to be toppled over, and the blow of the 

 air communicates a motion of rotation which 

 may cause one to roll under the train if the 

 nature of the ground does not prevent such re- 

 sult. It was remarked, however, that where 

 trains have a right to run at any speed no pru- 

 dent person would stand so near to a train as is 

 necessary in order to be in danger from this 

 source. 



The following officers were declared elected 

 for the year 1897 : President, M. L. Gray ; 

 First Vice-President, E. A. Engler ; Second 

 Vice-President, Charles E. Sanger ; Record- 

 ing Secretary, William Trelease ; Correspond- 

 ing Secretary, E. C. Runge ; Treasurer, Enno 

 Sander ; Librarian, G. Hambach ; Curators, 

 Julius Hurter, J. H. Kinealy, E. Evers; Di- 

 rectors, M. H. Post, Joseph Grindon. 



One person was elected to active member- 

 ship. 



William Teelease, 

 Recording Secretary. 



NORTHWESTERN UNIVERSITY SCIENCE CLUB. 



At the December meeting, Dr. Marcy in the 

 chair. Prof. Crook presented ' Some Geological 

 Causes of the Scenery of the Yellowstone 

 National Park ' as a report upon a trip to that 

 region. The nature of the scenery is due : 

 1, to the fact that the country is geologically 

 young, having begun to take its present form 

 at the close of the Cretaceous ; 2, to the fact 

 that it is composed of volcanic materials 

 which were erupted in this order, viz : Ande- 

 site, i-hyolite, basalt ; 3, to the fact that the 

 rhyolite is not yet cooled ; and 4, to the fact 

 that the topography of the country causes pre- 

 cipitation of meteoric waters unusually great 



for that region and, consequently, low tem-' 

 perature and powerful erosion. The difference 

 in chemical composition of the spring waters is 

 accounted for on petrographical grounds. 



Geyser action is satisfactorily explained in 

 accordance with Bunsen's theory. The unique 

 coloring in the region is due to biological and 

 to mineralogical causes. Twenty hand speci- 

 mens and thin sections and fifty lantern slide 

 views illustrated points considered. 



EvANSTON, III. A. R. Crook, 



Secretary. 



UNIVERSITY OF WISCONSIN SCIENCE CLUB, 

 DECEMBER 16, 1896. 



Prof. C. R. Van Hise, in his paper, ' The 

 Deformation of Rocks,' discussed the subject in 

 general. It was shown that, in order to ade- • 

 quately understand the phenomena of deforma- 

 tion, the position of rocks with reference to the 

 surface must be considered. Observations in 

 the field show that there are three somewhat 

 distinct zones — an outer zone of fracture, a 

 middle zone of combined fracture and folding, 

 and a deeper seated zone of folding. However, 

 whether folding or fracturing occurs depends 

 largely upon the rapidity of deformation and 

 upon the strength of the rock in question, as 

 well as the superincumbent load. Therefore 

 at the same depth may be found all the phe- 

 nomena of the zones of fracture and flowage ; 

 but, broadly stated, the outer zone is particu- 

 larly characterized by joints, faults and breccia- 

 tion ; the deep seated zone is particularly char- 

 acterized by folding and cleavage ; and the 

 middle zone shows all of these phenomena with 

 various complex relations. 



Mr. L. S. Cheyney, in his paper, ' R6sum6 of 

 Work done on the Flora of Wisconsin,' dis- 

 cussed briefly the history of systematic botan- 

 ical investigation upon the vegetation of the 

 territory now included in the limits of the State, 

 from the journeys of the Jesuit missionaries to 

 the present time. 



Mr. C. H. Ford, in his paper, ' The Modern 

 Telephone Transmitter,' gave an account of 

 some original work done to test the compara- 

 tive worth of modern transmitters. 



Wm. S. Marshall, 



Secretary. 



