warm. As a fact, however, we have had iS winters in 52 years 

 which were warmer. 



Prof. Nipher gave a short verbal statement of the development 

 and recent improvements in the construction of the Dynamo. 



April 1st, 1889. 

 President Nipher in the chair ; six members present. 

 Prof. Nipher made a few remarks showing how the magnetic 

 resistance of iron is determined. 



April 15M, 1889. 



President Nipher in the chair ; thirteen members present. 



A paper by Dr. Liideking on "The Electrical Conductivity of 

 Colloids" was referred to the Committee on Publication. 



A paper by Mr. J. H. Kinealy entitled "Mathematics of Venti- 

 lation" was read by Prof. Gale. 



A paper on "North American Rhamnacece" by Prof. Trelease 

 was read by title and referred to the Committee on Publication. 



May 6th, 1889. 



President Nipher in the chair ; six members present. 



Dr. Hambach reported for the Curators that the exchange of 

 fossils for pottery offered by Seever & Co. had been made, and 

 exhibited the fossils. 



Mr. Engler made some remarks on the refraction of parallel 

 rays of light through a sphere. 



Mr. Nipher gave a discussion of the action of transformers in 

 electric lighting by alternate currents. The discussion was main- 

 ly mathematical, and was participated in by other members. 



Mr. Seddon made some remarks on the time of complete dis- 

 charge of a reservoir as compared with the time of discharge at 

 a constant rate. 



