Record. xlix 



In this paper, which includes the theory of the mechanism exhibited 

 at the meeting of April 15, 1912, it is shown that not only for radial 

 spokes, but also for spokes in the form of logarithmic spirals, the 

 mechanism illustrates lines of force. By having several pairs of 

 wheels with different systems of logarithmic spirals (in particular, 

 of radial lines) it is possible, in virtue of the device for obtaining 

 different angular velocity ratios, to obtain a great number of dif- 

 ferent systems of curves, each of which may be regarded as lines 

 of force or stream lines in five or six different branches of mathe- 

 matical physics. It is possible, by making time exposures, to obtain 

 well-defined photographs of these systems of curves. This possibility 

 adds to the usefulness of the mechanism. The mechanism and pho- 

 tographs of some of the systems of curves were exhibited. 



Dr. D. L. Harris read a paper on ^'Experimental Work 

 on the Etiology of Rabies and the Mechanism of Anti- 

 Rabio Immunity." 



Professor W. H. Roever, Mr. Frank Schwarz and Dr. 

 R. J. Terry were elected a committee to nominate officers 

 for the year 1913. 



December 16, 1912. 



President Engler in the chair; attendance 32. 

 The following report of the Nominating Committee 

 was read: 



St Louis, Mo., Dec. 16, 1912. 

 The Academy of Science, 



St. Louis, Mo. 

 Gentlemen: The nominating committee, appointed at the meet- 

 ing of December 2, 1912, begs to submit the following nominees for 

 offices for the year 1913: 



For President Edmund A. Engler. 



For First Vice-President Francis E. Nipher. 



For Second Vice-President Arthur E. Ewing. 



For Recording Secretary J. A. Drushel. 



For Corresponding Secretary Geo. O. James. 



For Treasurer H. E. Wiedemann. 



For Librarian Wm. L. R. Gifford. 



For Curators Julius Hurter, Philip 



Rau, Hermann von 

 Schrenk. 

 For Directors Adolf Alt, H. M. Whelp- 

 ley. 

 Respectfully submitted, 



(Signed) Wm. H. Roeveb, 

 Frank Schwarz. 

 Robert J. Terry. 



