964 



SCIENCE. 



[N. S. Vol. IV. No. 104. 



proceeding from a system consisting of an elec- 

 trified plane and an electrified line parallel to 

 the plane, is the locus of the intersection of 

 two straight lines having motions in a plane 

 which is perpendicular to the electrified line ; 

 one line having a motion of uniform rotation 

 about the electrified line as an axis, and the 

 other a motion of uniform translation perpen- 

 dicular to itself and parallel to the electrified 

 plane. 



(b) That the curve representing a line of force 

 proceeding from a system consisting of an elec- 

 trified plane and an electrified point is the 

 locus of intersection of two straight lines having 

 motions in a plane, which passes through the 

 electrified point and is perpendicular to the 

 electrified plane ; one line having a motion of 

 rotation about the electrified point and the other 

 a motion of translation perpendicular to itself 

 and parallel to the electrified plane. The rota- 

 tion is such that the versine of the angle which 

 the rotating line makes with oy (a line which 

 passes through the electrified point and is per- 

 pendicular to the electrified plane) changes at a 

 uniform rate, and the translation is such that if 

 the moving line were the meridian line of a cyl- 

 inder of revolution whose axis is oj^ the area of 

 cross section of the cylinder would change at a 

 uniform rate. 



Mr. Roever also showed other properties of 

 the above lines of force. 



One active member was elected. 



William Trelease, 

 Recording Secretory. 



SCIENCE CLUB AT THE UNIVERSITY OF 

 WISCONSIN. 



The first regular meeting of the Science Club 

 of the University of Wisconsin M^as held Tues- 

 day, November 10th, the regular programme 

 consisting of a discussion by E. A. Birge on 

 • The Crustacea of the Open Water of Lake 

 Mendota,' and a paper on 'the Radiophone' 

 by C. M. Smith. Mr. Birge, in speaking of the 

 vertical distribution of the limnetic Crustacea, 

 enumerated the factors which efiect the distri- 

 bution, and illustrated the action of each factor 

 by its effect on different species of the Crustacea. 

 Especial attention was called to the fact that in 

 summer the Crustacea do not descend below the 



' Sprungschicht ' of temperature, but stop ab- 

 ruptly at that level. This was regarded as due, 

 not to temperature directly, but to the accu- 

 mulation of decomposition products in the 

 deeper water. Mr. Smith's paper reviewed the 

 principal phenomena which have led to the 

 conclusion that the production of sounds of 

 definite pitch is a general property of all mat- 

 ter, whether solid, liquid or gaseous, when 

 placed in the path of rapidly intermitted heat 

 radiations ; the pitch corresponding to the 

 rapidity of interruptions of the rays. He 

 further showed the application of the method 

 to the study of emission and absorption phe- 

 nomena. Wm. S. Marshall, 



Secretary, 



THE BOTANICAL SEMINAR OF THE UNIVERSITY 

 OF NEBRASKA, DECEMBER 5, 1896. 



The Polyphyletic Grouping of the Lichens, Mr. 

 Clements. Mycological Statistics of Nebraska, 

 Mr. Pound. The Comparative Anatomy of the 

 Pistil in Apocarpous Families, Mr. Ernst Bes- 

 SEY. Phytogeographical Notes from Colorado, 

 Mr. Shear. 



NEW BOOKS. 



The Microscope and Microscopical Methods. Simon 

 Henry Gage. Ithaca, Comstock Publishing 

 Co. 1896. Pp. xii+237. $1.50. 



The Principles of Sociology. Herbert Spencer. 

 New York, D. A-ppleton & Co. 1896. Vol. 

 ni., pp. x+645. $2. 



List of the Vertebrated Animals now or lately living 

 in the Gardens of the Zoological Society of Lon- 

 don. London, Longmans, Green & Co. 1896. 

 Pp. xvi+724. 



Prehistoric Man and Beast. H. N. Hutchinson, 

 New York, D. Appleton & Co. 1897. Pp. 

 xxi+298. $3. 



A Textbook of Special Pathological Anatomy. 

 Ernst Ziegler. Translated and edited 

 from the Eighth German Edition by Donald 

 MacAlister and Henry W. Cattell. New 

 York and London, The Macmillan Co. 1896. 

 Section L-VHI. Pp. xix+575+xxxii. 



Elementary Meteorology for Sigh Schools and Col- 

 leges. Frank Waldo. New York, Cincin- 

 nati and Chicago, The American Book Com- 

 pany. 1896. Pp. 372. 



