March 30, 1905] 



NATURE 



517 



order in terms of initial values, and Prof. L. Wayland 

 Dowling discusses the conformal representation of triangles, 

 with special reference to cases in which the solution can be 

 represented by hyperelliptic integrals of given deficiency. 



In a contribution to the Berlin Silziitigsbcrichte (1904, 

 lii.), read December 8, Prof. Leo Koenigsberger discusses 

 the extension of the principle of energy to a system having 

 a kinetic potential of any order, and any number of vari- 

 ables dependent and independent. The paper forms a con- 

 tinuation of Prof. Koenigsberger 's researches on the 

 dynamics of systems in which time, instead of being one 

 dimensional, may be of two or more dimensions. 



Prof. Garhasso has published a short note (Genoa, 

 Angelo Ciminago, 1904) in which he proposes a new theory 

 to account for the duplication of lines in the spectra of 

 variable stars. .According to this theory, it is assumed that 

 the phenomena are due to the presence of an element the 

 atoms of which are formed of two separate conductors, and 

 that these atoms are mostly in a state of dissociation. The 

 paper consists of a mathematical investigation of the 

 periods of a system of electric oscillators forming a model 

 of the supposed atoms. 



In 1890 a paper was presented to the Lincei .\cademy by 

 Prof. Filippo Keller entitled " .'\n itinerary guide to the 

 principal magnetic rocks of Latium," of which only an 

 abstract was printed. Since Prof. Keller's death in 1903 

 the complete paper has been brought out by Dr. G. Fol- 

 gheraiter as No. 1 1 of his series of Frammenti dealing 

 with the geophysics of the environs of Rome. It is ac- 

 companied by a map of the district and a portrait and bio- 

 graphical notice of Keller, the latter by Prof. S. Giinther. 

 It is printed by Panetto and Petrelli, of Spoleto. 



The Revue gen^rale des Sciences for February 28 con- 

 tains a reprint of the paper read at Breslau by Dr. A. 

 Kohler (Jena) on photomicrography by ultra-violet-light. It is 

 illustrated by figures showing the arrangement of the micro- 

 scope and camera, and the illuminating apparatus. It is 

 pointed out that, independently of the increase of resolving 

 power, ultra-violet light often affords a method of differ- 

 entiating between organic tissues in virtue of their different 

 degrees of transparency to the rays, and, further, it in 

 some cases can be used to excite interesting phenomena of 

 fluorescence in microscopic objects. 



The Atti dei Lincei, xiv. (i) 3, contains a short account 

 of some experiments by Mr. Alessandro Artom on wireless 

 telegraphy with the use of circular or elliptically polarised 

 waves. The experiments were divided into four groups, 

 and in every case established the predicted property that it 

 would be possible to send methods in definite directions by 

 the use of these waves. Thus, in the last series of experi- 

 ments, signals were sent from Monte Mario (Rome) to the 

 island of Maddalena without any effects being noticed at 

 the island of Ponza, which is situated some way off the line 

 joining the first two stations. Further, it appears that with 

 the use of circular waves the height of the aerial conductors 

 can be reduced. 



Thb ninth supplement to the present series of Communi- 

 cation; from the Physical Laboratory of the University of 

 Leyden contains an address delivered in commemoration of 

 the 329th anniversary of the University of Leyden by Dr. 

 H. Kamerlingh Onnes, Rector Magnificus of the university. 

 It deals with the importance of accurate measurements at 

 very low temperatures, a need which, it is pointed out, was 

 first appreciated by Boyle. An important application of such 

 observations has arisen in connection with van der Waals's 

 NO. 1848, VOL. 71] 



theory of corresponding states, and Dr. Onnes points out 

 that further researches at low temperatures are required for 

 the problems of the mechanism of the atom that have been 

 forced upon us by recent discoveries. Dr. Onnes empha- 

 sises the very important work done by Dewar in rendering 

 such low temperature observations possible. 



" Mathem.^tic.^l Progress in America " forms the subject 

 of Prof. Thomas B. Fiske's address to the .'\merican 

 Mathematical Society published in the Bulletin of the 

 society for February. Prof. Fiske divides the history of 

 pure mathematics in America into three periods, the first 

 extending up to the foundation of the Johns Hopkins Uni- 

 versity in 1876, the second extending from 1876 to 1891, 

 when the New York Mathematical Society was converted 

 into the present .'\merican Mathematical Society and began 

 to issue the Bulletin, and the third covering recent times. 

 The Bulletin contains, further, the continuation of the re- 

 port on last summer's congress at Heidelberg by Dr. E. B. 

 Wilson, and a report of the meeting of the Deutsche Mathe- 

 matiker Vereinigung by Mr. R. E. Wilson. The Bulletin 

 thus furnishes a summary of mathematical progress of a 

 cosmopolitan character such as does not exist in this 

 country. 



Of the increasing attention which is being devoted on 

 the Continent to the history of the sciences, and in particular 

 to that of mathematics, abundant proof is afforded by vol. 

 xii. of the Atti of the International Congress of Historical 

 Sciences, which met in Rome in April, 1903. This volume 

 is devoted entirely to the proceedings of the section which 

 dealt with the history of mathematical, physical, natural, 

 and medical sciences, and it occupies 330 pages. It includes 

 general discussions by Prof. Ella Millosevich on the icon- 

 ography of solar eclipses, by M. Paul Tannery dealing with 

 proposals for advancing the history of science, some remarks 

 by Messrs. D. Barduzzi, P. Giacosa, and Gino Loria on 

 the introduction of university courses on history of sciences, 

 and proposals by Prof. Gino Loria for the publication of 

 Torricelli's works, and by Prof. Pietro Giacosa for a cata- 

 logue of the scientific manuscripts in Italian libraries and 

 archives. Among the papers read, the two mathematicians 

 associated with the solution of the cubic, Tartaglia and 

 Cardan, receive mention at the hands of Mr. Tonni-Bazza 

 and Prof. Moritz Cantor ; Prof. M. Darvai deals with the 

 life of Bolyai ; Prof. A. von Braunmiihl contributes an 

 interesting paper on the history of the integral calculus ; 

 Prof. R. Amalgia writes on early theories of the tides ; 

 Prof. Icilio Guareschi on the alleged plagiarisms of 

 Lavoisier. Altogether the volume contains no less than 

 thirty-four papers. 



Attention has already been directed to the important 

 series of papers on applied mathematics now being issued 

 by Prof. Karl Pearson, F.R.S., under the title " Drapers' 

 Company Research Memoirs." Two further numbers have 

 now reached us. One of them is the fourteenth of Prof. 

 Pearson's mathematical contributions to the theory of evo- 

 lution, and deals with skew correlation and non-linear re- 

 gression. The highly specialised character of the work may 

 be inferred by quoting one of four conclusions on p. 53 : — 

 " The correlation between auricular height of head and age 

 in girls is cubical, of nomic heteroscedasticity and of 

 anomic heteroclisy. It is probably really a case of isocur- 

 tosis." The other paper is by Mr. L. W. Atcherley and 

 Prof. Pearson, and deals with the graphics of metal arches. 

 In it the authors point out the impossibility of applying 

 purely graphical constructions with any degree of accuracy 

 to the very flat metal arches used in modern bridges, and, 

 they propose a kind of " semi-graphical " method, depend- 



