July 19, 1900] 



NA TURE 



269 



LETTERS TO THE EDITOR. 



[ The Editi^r does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond 7vith the writers of, rejected 

 .^mannscripts intended for this or any other part of NaI UKK. 

 \f^o notice is taken of anonymous commtinications.^ 



A Surface-tension Experiment. 



Sans rien vouloir enlever a Tinteret de I'experience d'hydro- 

 dynamique signalee par Mr. Baker (p. 196), je crois pouvoir 

 dire qu'elle n'est pas nouvelle, au moins, en tant que 

 phenomene. 



Ces sortes de formations de " vasques " liquides etaient tres 

 usitees, dans les jardins au XVIIeme siecleetnous en rencontrons 

 encore aujourd'hui des exemples dans les pares oil le regime 

 des eaux n'a pas change depuis cette epoque. Pour n'en citer 

 qu'un. que connaissent sans doute beaucoup de vos lecteurs. je 

 rappelerai qu' a Burgos le " paseo del Espalon viejo" possede 

 une fontaine 011 Ton peut voir une belle realisation de cette ex- 

 perience. Seulement, la le jet d'eau est dirige de bas en haut 

 et vient se briser sur un disque place horizontalement au dessus 

 de lui ; puis retombant, il forme autour du tuyau la surface 

 t'ernue si elegante decrite par M. Baker. 



Je crois me souvenir que dans un ouvrage public en 1663 a 

 Nuremberg par George Andre Boeckler sous le titre " Archi- 

 tecturacuriosanova," ily a de nombreuses planches representant 

 des jets d'eau d'etfets tres varies. Peut etre la forme signalee 

 par Mr. Baker s'y trouve-t-elle ? 



11 serait interessant de le verifier, comme aussi de chercher la 

 figure malhematique de cette surface fermee. 



Henry Bourget, 

 de rUniversite de Toulouse. 



Duration of Totality of Solar Eclipses at Greenwich. 



In Nature (vol. Ixii. p. 64 and p. 86) will be founJ an 

 estimate of the maximum duration of totality for a solar eclipse 

 under the most favourable conditions, the result being 7m. 40s 

 for a place in norih latitude 4° 52'. For Greenwich I estimate 

 the maximum duration at 5m. 47s. There is good evidence for 

 believing that the "Nautical Almanac " diameter of the mo<m, 

 used in computing eclipses, is too large. It is almost exactly 

 2160 miles, and should be reduced probably to 2158 miles. This 

 reduction would alter the above estimates to 7m. 34s. and 

 5m. 42s. respectively. That all the conditions necessary to 

 produce the maximum totality of 5m. 42s. will ever be simul- 

 taneously satisfied for Greenwich is extremely improbable. 



Leeds, July 14. Chas. T. Whit.mell. 



THE NEIV YORK MEETING OF THE 

 AMERICAN ASSOCIATION. 

 A T the forty-ninth meeting of the American Associa- 

 -^*- tion for the Advancement of Science, which was 

 held on June 23-30, at Columbia University, New York 

 City, two experiments were tried. The one was a change 

 of date and the other a somewhat radical change in the 

 character of the meeting. Heretofore, it may be remem- 

 bered, the American .Association has met at about the 

 third week in August, approximately at the saine time as 

 the meeting of the British Association. The long 

 summer vacation of the American colleges and uni- 

 versities usually lasts from about the end of June until 

 nearly the beginning of October, It therefore resulted 

 that men engaged in educational work were obliged to 

 interrupt their sumriiers at the seaside or the mountains, 

 to attend the Association meetings. This has been found 

 to be very inconvenient to many on account of the long 

 distances in the States and the widely separated places 

 of meeting. The present year was thought to be a 

 particularly favourable one in which to try a change of 

 date, since many members expected to start for Europe 

 after the close of their college terms, and New York, as 

 the principal port of debarkation, was chosen as the place 

 of meeting for much the same reason. 



The other experiment was in the doing away, to a large 

 extent, with the social features and entertainments which 

 had characterised previous meetings. It was distinctly 



NO. 1603. VOL 62] 



understood that no entertainment fund would be raised in 

 New York, and that the Association would pay its own 

 expenses. It was, therefore, a more distinctively 

 working scientific meeting than has been held before. 

 The attendance was not large, and only 450 members 

 registered. Fifteen affiliated societies held their meetings 

 at the same time, including several which have heretofore 

 not affiliated themselves with the older society. These 

 were the American Mathematical Society, the .American 

 Physical Society, and the American Psychological 

 Association. The other societies in attendance were 

 the American Forestry Association, the Geological 

 Society of America, the American Chemical Society, 

 the Society for the Promotion of Agricultural Science, 

 the Association of Economic Entomologists, the 

 Botanical Society of America, the Society for the Pro- 

 motion of Engineering, Education, the American Folk- 

 Lore Society, and the American Microscopical Society. 



The session was opened by the retiring President, 

 Mr. G. K. Gilbert, who was elected at the December 

 meeting of the Council to fill the vacancy caused by the 

 death of Dr. Edward Orton last autumn. Mr. Gilbert 

 introduced the incoming President, Prof. R. S. Woodward, 

 of Columbia University, who thereafter presided over all 

 the general sessions of the Association. A cordial and 

 eloquent address of welcome was made by Mr. Seth Low, 

 President of Columbia University ; and Mr. James Wilson, 

 the Secretary of Agriculture in President McKinley's 

 Cabinet, upon being invited to address the Association, 

 made a strong plea for applied science. On Tuesday 

 afternoon the addresses of five of the Vice-Presidents were 

 given, the other four being postponed until next year. 



Vice-President Asaph Hall,junr., addressed the Section 

 of Mathematics and Astronomy on the teaching of astro- 

 nomy in the United States. Prof. Hall urged that 

 elementary astronomy should be taught in the high 

 schools and preparatory schools as well as in the 

 colleges. Elementary astronomy he defines as meaning 

 such part of the science as can be learned by an intelli- 

 gent student without mathematical training. He advo- 

 cated the study of the history of astronomy as a culture 

 study in the colleges, showing that the earliest religious 

 festivals depended upon astronomical observations. An 

 interesting feature of this historical side would be the 

 philosophical study of the different theories of the 

 universe. He advocated the more general teaching of 

 spherical astronomy and the elements of celestial 

 mechanics, and showed that during the past twenty years 

 great advances in astronomical teaching have been made 

 in the States. In his opinion the best equipped observ- 

 atory for teaching purposes is at Princeton, and the theses 

 in practical astronomy produced in America compare 

 favourably with those presented in Germany and France. 



Vice-President Merritt addressed the Section on 

 Physics on the subject of " Kathode Rays and some 

 Related Phenomena," referring to the various views 

 which have been advanced concerning the nature of the 

 kathode rays, and the general adoption of the Crookes' 

 theory of electrified particles. He gave an account of 

 the progress made during the last ten years, and dis- 

 cussed recent experiments concerning the size of the ray 

 particles and the speed at which they travel. Minor 

 difficulties in the present theory were pointed out, and 

 the probable direction of further progress was indicated. 

 Lantern views were shown illustrating various vacuum 

 tube phenomena related to kathode rays. 



The address of Vice-President Howe before the Section 

 of Chemistry was on the subject, " The Eighth Group of 

 the Periodic System and some of its Problems." It was 

 pointed out that in the early work of Newlands and 

 of Mendeleeff, which subsequently developed into the 

 periodic law, a serious difficulty was met with in dealing 

 with iron, cobalt, nickel, and the metals of the platinum 

 group. 



