xlvii 



November i^tk^ 1890, 



President Nipher in the chair ; twelve members presen, afso 

 two visitors. 



Dr. Hinrichs presented to the Library a number of papers on 

 Molecular Science, published in the proceedings of the American 

 Association for the Advancement of Science, the Academy of Sci- 

 ence of Vienna, the Comptes Rendus of the Academy of Science 

 of Paris, and others printed separately; also "The Principles of 

 Chemistry and Molecular Mechanics," of 1874 ; for which he re- 

 ceived a vote of thanks. 



Mr. Engler made some remarks concerning the properties of 

 the Cone of Revolution. 



Prof. Nipher exhibited and described a Westinghouse Trans- 

 former. 



Prof. Wheeler exhibited and described some quartz crystals 

 from Hot Springs, Arkansas, which beautifully showed the phe- 

 nomena of "Ghosts" or "Phantoms" ; also a specimen showing 

 bubble inclosures about J of an inch in diameter ; also a fire- 

 opal from Mexico. 



December 1st, 1890. 



President Nipher in the chair ; twelve members preseut. 



Dr. Hinrichs made some remarks on the normal paraffin series 

 of hydro-carbons. He said this series was now known with a 

 sufficient degree of accuracy to warrant him to more fully inves- 

 tigate the general laws of their boiling and fusing points ; this he 

 has done, and will present the results at the next meeting. 



Prof. Nipher made some remarks on the output of an electric 

 motor. Taking the horse-power, current, and potential of the 

 mains as coordinates, he showed that the power applied to the 

 motor, and the power delivered by the motor, were represented 

 by hyperbolic paraboloids. 



December i$t^, 1890. 



President Nipher in the chair ; thirteen members present. 

 Dr. Hinrichs presented the introduction to his " Contributions 

 to Atom-Mechanics." 



