644 



SCIENCE. 



[N. S. Vol. III. No. 69, 



Steel Rails of Uniform Physical Properties Fol- 

 lows the Comparative Moments of Inertia of the 

 Eespective Sections.' Mr. Dudley described 

 the improvements in the manufacture of steel 

 rails which has been carried out under his di- 

 rection during the last five years. The object 

 was to produce a much stiffer rail than that 

 which had been previously employed, and at 

 the same time to make one out of a higher 

 grade of steel. The rails have now been in use 

 several years on the Boston & Albany and New 

 York Central railroads, and they show a 

 marked improvement over the old patterns in 

 that the deflections have been decidedly less- 

 ened. Careful records of them have been kept 

 by means of Mr. Dudley's track inspection ma- 

 chine. A great deal of information has also 

 been accumulated by Mr. Dudley in connection 

 with the tests of samples from each heat of steel 

 in the process of manufacture. The full paper 

 will be subsequently published by the Academy. 



In the absence of Prof Jacoby the contents 

 of his paper on ' The Permanence of the Ruth- 

 erfurd Photographs ' were briefly summarized 

 by Prof Rees. Recent and very careful meas- 

 urements made upon Rutherfurd negatives, 

 which had been developed twenty or thirty 

 years ago and which had been measured five to 

 ten years ago, show absolutelj' no change in the 

 plates, so far as could be detected. The film 

 remains in the same part of the glass as when 

 first studied. The negatives were made upon 

 wet plates, and the speaker remarked that it 

 remains to be shown whether the newer dry 

 plates afford the same permanence. 



The next paper was by Prof. J. K. Rees, on : 

 (1) ' The Harvard College Observatory photo- 

 graphs of star clusters, planets, variable stars 

 and stellar spectra.' (2) 'Prof J. E. Keeler's 

 photographs of planetary spectra. ' Prof Rees 

 exhibited a large series of photographs of va- 

 rious astronomical subjects, which had been 

 loaned by Prof Pickering, of the Harvard Ob- 

 servatory, for the recent exhibition of the New 

 York Academy of Sciences. He also threw 

 upon the screen, by means of the lantern, a 

 series of photographs of star clusters which in- 

 cluded variable stars, and which show these 

 variables at different periods. The originals 

 were taken at the Harvard Observatory. 



In the second part of his paper Prof Rees 

 threw upon the screen enlargements from pho- 

 tographs of stellar spectra which had been taken 

 by Prof. Keeler, of the Observatory at Alle- 

 gheny, Pa. The photographs of the spectra of 

 Saturn were also shown, which prove that the 

 ring about the planet is due to a stream of me- 

 teorites. 



The last paper of the evening was the follow- 

 ing by Prof M. I. Pupin : ' Communication of 

 some new Results of Experiments with the 

 Eontgen rays. ' This paper was printed in full 

 in Science. April 10. Experimental demon- 

 stration of the points advanced was subse- 

 quently made for the members of the Academy 

 in Prof Pupin's laboratory. 



J. F. Kemp, 



Secretary. 



NORTHWESTERN UNIVERSITY SCIENCE CLUB. 



At the meeting of March 6th, Dr. Marcy in 

 the chair, papers were presented by the Depart- 

 ment of Mathematics. 



Prof. Holgate gave the ' Problem of the Eight 

 Queens,' which is so to place eight queens on a 

 chessboard that no one will be endangered by 

 any other, or, in general, to place n pieces on a 

 square board so that no two will be in the same 

 row, same column, or same diagonal. This 

 problem was first proposed by Nauck to Gauss, 

 was the subject of correspondence between 

 Gauss and Schumacher and was finally solved 

 by Gauss in 1850. In 1874 Giinther suggested a 

 solution of which Glaisher made use in a solu- 

 tion which he published that year iu the Philo- 

 sophical Magazine. Dr. Holgate presented 

 Glaisher' s solution in full. 



Prof White presented Poncelet's problem 

 concerning polygons that possess both an in- 

 scribed and circumscribed conic. The para- 

 metric representations of the points of a conic, 

 the doubly quadric relations of pairs of points, 

 and the statement of periodic relations of this 

 kind by the aid of elliptic functions, were 

 treated in the manner of Euler, Jacobi and 

 Hurwitz. A. R. Crook, 



Secretary. 



EvANSTON, III. 



Erratum: — On page 604, paragraph 2, line 2, for 

 Instinct read Insect. 



