November 25, 1909] 



jVA TURE 



107 



oil, paper, and water analysis, in addition to general 

 bacteriological and chemical apparatus. The volume will 

 make a very useful addition to the laboratory library of 

 working books ; its numerous illustrations, concise descrip- 

 tions of the more complicated instruments, and orderly 

 arrangement will prove real aids to the selection of labora- 

 tory apparatus. 



The librarian of the Library of Congress, Washington, 

 has issued two " Want Lists," each running to more than 

 two hundred pages, one dealing with the publications of 

 societies and the other with periodicals. In a prefatory 

 note to each volume, librarians and secretaries of institu- 

 tions receiving copies of the lists are asked to check them 

 and to notify the Library of Congress of any duplicates 

 at their disposal which may help to complete the files of 

 the Washington library. We observe that certain copies 

 of Nature are in request ; perhaps some of cur readers 

 may have duplicate copies of the following issues, now out 

 of print, which the librarian of Congress would be glad to 

 receive : — 1899 — May 4, June 15, 22, July 6 to August 10, 

 September 14, and title and index; igoi — August i, i6 to 

 October 10, 24, 31, and title and inde.x. Librarians 

 are invited to send to the Library of Congress lists of 

 their wants, as there is at Washington a stock of duplicates 

 available for exchange. 



OUR ASTRONOMICAL COLUMN. 



Atmospheric Refraction. — The Rev. W. Hall, Chaplain 

 Instructor, R.N., has circulated a typescript article on 

 " Refraction in Relation to Astronomical Navigation." It 

 is short and clearly expressed ; nothing is assumed as 

 already known, and yet the reader is taken to the furthest 

 limits required for the writer's purpose. The article is 

 therefore a model of what such articles should be. 



For purposes of refraction, rays fall under three 

 classes : — (i) a ray from a high star; (2) a ray from a low 

 star ; (3) a ray from the horizon finally reaching the 

 observer's eye a few feet above sea-level, but ten miles 

 from his horizon. The second ray is outside the scope of 

 the article, as navigators ought not to observe low stars. 

 The other two rays are considered in detail, and full 

 advantage is taken of the simplifications rendered possible 

 in one case by the altitude of the star and in the other by 

 the thinness of the stratum of the atmosphere traversed. 

 Proper warning is given that the state of the atmosphere 

 at the horizon may not correspond to the barometer and 

 thermometer readings on board ship. 



The Spectrum of Halley's Comet. — Using a slitless 

 spectroscope, attached to the Crossley telescope, Mr. W. H. 

 Wright succeeded in photographing the spectrum of 

 Halley's comet on October 22, about 180 days before the 

 computed perihelion passage. 



Two hours' effective exposure was given, the guiding 

 being effected by a movable micrometer attached to the 

 telescope. The plate shows a faint continuous spectrum 

 extending from about A. 3750 to X 5000, and there is no 

 evidence of the existence of any bright lines or bands 

 characteristic of most cometary spectra ; the spectrum is 

 too faint to determine the presence, or absence, of dark 

 lines (Lick Observatory Bulletin, No. 167). 



Seasonal Change on Mars. — ^Through the Kiel Central- 

 stelle (Circular No. 115, November 18) Prof. Lowell 

 announces that the first apparent Antarctic snowfall of 

 the season has taken place on Mars. Two patches have 

 appeared in latitude 65°, one in longitude 100°, the other 

 in 100°. 



Other changes and new features are announced by MM. 

 Antoniadi, Qu^nisset, and J. Comas Sola, respectively, in 

 the November number of the Bulletin de la Sociite 

 astronomique de France. M. Antoniadi reproduces, on 

 four plates, four drawings of the planet made during 

 September and October, and gives several conclusions to 

 which he has been led by his observations at this opposi- 

 tion. Among these we notice that he affirms the superiority 

 of larger instruments in observations of Mars. He also 

 finds that the grey areas are subject to great modifications 

 NO. 2091, VOL. 82] 



of contour, although the Syrtis Major now has the same 

 aspect as in 1S64. As regards the objective existence of 

 ''canals," M. Antoniadi urges that care should be taken 

 in the nomenclature ; some of these features are un- 

 doubtedly real and persistent, others have an undulated 

 appearance and are more or less fugitive. He concludes 

 ^y suggesting that with more powerful equipment the 

 apparent geometrical arrangements would give place to 

 irregularities both of form and tone. 



Among other observations, M. Qu^nisset directs attention 

 to the unusual dimensions of the Lacus Moeris and to the 

 apparent periodicity of a canal to the south-west of Nectar. 

 M. Sola describes his observations of the Lacus Soils, 

 and believes he has seen it triple, while he suggests that 

 the two canals. Nectar and Bathys, are really made up by 

 alignments of small " lakes " imperfectly seen, the latter 

 canal being much more easily seen than in many previous 

 oppositions. Pons Juventje, seen in 1907, has remained' 

 absolutely invisible to him during the present opposition. 



The Perseid Meteors in igoq. — During July and August 

 watch was kept, at the Lick Observatory, for the August 

 meteors, and on nine nights 755 meteors were seen. A 

 special watch was kept on August 10 and 11, and 220- 

 meteors were seen. July Perseids were exceptionally scarce 

 and faint, and the maximum of the shower occurred on 

 .August II, the horary rate, during a continuous watch- 

 lasting from iih. 17m to I4h. 41m., being 117. Mr. 

 Oliver states that the radiant appeared to cover a large 

 \] area, and there was difficulty in separating it from the 



.radiants of the contemporaneous minor showers. 



\ A D.1YLIGIIT Meteor.— Dr. Palisa records the telescopic 

 appearance of a meteor on September 4 at 10.30 a m 

 Whilst making a daylight observation of Castor he was- 

 looking through a 1.5-inch finder, having a field of 2° and' 

 saw a bright object cross the field. The velocity' was- 

 small, and the shape was rather square than circular • the 

 direction was from east to west, and the object was sur- 

 prisingly large, appearing at least as bright as Venus 

 {Astronomische Nachrichten, No. 4367). 



Spectroscopic Binaries.— In No. 3 vol. x.xx of the 

 Astrophysical Journal, Dr. S. A. Mitchell publishes par- 

 ticulars of seven spectroscopic binaries, determined from 

 plates taken at the Yerkes Observatory and measured at 

 the Columbia University. The stars dealt with are- 

 /3 Equulei, $ Tnanguli, 7 Lvr;E, Virginis, o 78 Virginis 

 ^4 o- Cams Majoris, and s." Canis Majoris. 



The " Annuaire " of the Bureau des Longitudes, 

 1910.— We have received a copy of this " Annuaire," which 

 IS too well known to require detailed description • but it 

 should be remarked that, in accordance with the innova- 

 tion of 1904, the chemical and physical data are given 

 this year and geographical and statistical data omitted 

 Similarly, in the astronomical section, the tables of stellar 

 parallaxes, double stars, proper motions, &c., are omitted 

 and a complete list of the elements of the minor planets 

 is published ; about Soo of these objects are now included 

 The ' Annuaire " also contains articles on the reunion of' 

 the International Committee for the Carte du del, and on 

 tides. 



CONFERENCE ON MALARIA IN INDIA. 

 J\^ FURTHER stage in the campaign against malaria 

 has been reached by the inauguration of a conference 

 on malaria at Simla under Government auspices, a report 

 of the proceedings of which appears in the Pioneer Mail 

 of October 15 and 22. 



The proceedings were opened with an address by the 

 Viceroy, who, after welcoming the delegates on behalf of 

 the Government, pointed out how grievously India has 

 suffered from the scourge of malaria, which is probably 

 responsible in an ordinary season for one million deaths 

 in the year and for 100 million cases of fever that are not 

 fatal. The prevention of malaria depended upon the 

 extermination of the malaria-carrying mosquitoes, on the 

 prevention of their bites, and on the prophylactic use of 

 quinine. The extermination of the mosquito was largely 

 a question of administration and finance and of the develop- 

 ment of sanitation. 



.^n address was then delivered by Colonel Leslie, I.M.S., 

 Sanitary Commissioner with the Government of India. He- 



