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SCIENCE. 



[N. S. Vol. XII. No. 290. 



and it was shown that negatively charged 

 particles were thrown ofif which possessed 

 the properties of the cathode rays in that 

 they were reflectible by magnetism, carried 

 negative charges and rendered air conduct- 

 ing. Crookes theory of the nature of the 

 cathode rays is thus abundantly fortified. 

 Merritt's Vice-Presidential address was on 

 a similar subject, and evoked great interest. 



In a paper on 'A New Theory of the Elec- 

 tromagnetic Rotation of Light,' the writer 

 showed that whenever light is absorbed 

 certain phase relations between the electric 

 and magnetic forces and fluxes in the wave 

 are shifted in such a way as to make the 

 plane of the wave rotate when placed in a 

 magnetic field, and evidence was given 

 tending to show that this is a sufficient and 

 probable explanation of the phenomenon. 



A paper by Professor F. A. Bigelow on 

 the method of reducing barometric observa- 

 tion was unfortunately read by title onlj^, as 

 it seemed, from the abstract, to contain some 

 very valuable suggestions and data. Two 

 papers were read by Professor Franklin, 

 one on ' Lecture Eoom Demonstrations of 

 the Elementary Theory of Elasticity,' in 

 which some extremely ingenious methods 

 of illustrating such phenomena were given ; 

 the other a more abstract and mathematical 

 paper upon ' The Flow of Energy round a 

 Conducting Screen near a Current Sheet.' 

 Other papers read before this section were 

 those of Anthony, ' An Observation upon 

 the Surface Tension of Mercury' ; Knipp, 

 'Surface Tension of Water above 100°'; 

 Eeed, ' On Temperature Effects on a Tun- 

 ing Fork' (the last two containing a large 

 amount of very valuable experimental 

 data) . Edward Atkinson read a paper on 

 ' The Diffusion of Light,' treating the ques- 

 tion from the standpoint of the manufac- 

 turer's and insurance company's standpoint. 

 As Mr. Atkinson's work has been one 

 of the chief determining factors in the 

 method of lighting large factories in l^ew 



England and elsewhere, his remarks were 

 of more than general interst. He brought 

 out the interesting fact that, whilst fire 

 losses in the days of gas had been very high, 

 electric lighting, installed under the regu- 

 lations which he and his companies had 

 drawn up, had brought them down to al- 

 most a negligible amount. The papers, 

 ' The Percentage Bridge and its Applica- 

 tions,' by H. C. Parker ; ' Power Curves 

 from Alternating Current Circuits,' by 

 Rosa ; ' Circuit Breakers and Induction 

 Coils' and ' Experiments in Electric Light- 

 ing' by the writer, covered various forms of 

 apparatus. Some very beautiful photo- 

 graphs of electrical discharges were shown 

 by T. B. Kinraide, and though the section 

 did not apparently agree at all with his 

 theories, all were united in their apprecia- 

 tion of the results obtained and of the ap- 

 paratus used in their production. Other 

 papers which may be mentioned are those 

 by Professor Carhart ' On the Thermody- 

 namics of the Voltaic Cell' ; C. H. Williams, 

 ' On an Improved Lantern for Testing 

 Color Perception' ; A. D. Cole, ' On the use 

 of the Capillary Electrometer' describing 

 an interesting modification, much more 

 sensitive than the usual form ; and the 

 paper by I. S. Stevens, ' On a Method for 

 Measuring Surface Tension.' As a whole it 

 will be seen that the standard of the papers 

 read was of a very high order, and of more 

 than usual interest. 



It will be impossible to mm-e than men- 

 tion a few of the papers which were read 

 before the Physical Society : Reese, ' On 

 Zeeman Effect '; Potts, ' On Electric Ab- 

 sorption in Condensers '; Dorsey, ' On the 

 Polarization of the Solar Corona '; Mchols, 

 ' Preliminary Tests on the Efficiency of 

 Acetylene Flame as a means of Illumina- 

 tion ' ; Tufts, ' On Some Simple Apparatus 

 for the Study of Aerial Vibration '; Knipp, 

 ' On the Use of the Bicycle Wheel in Illus- 

 trating the Principles of the Gyroscope '; 



