September 17, 1903] 



NATURE 



491 



and the other observations of the survey staff, and the 

 series of articles will, it is hoped, when completed, form a 

 worthy memorial of the late Mr. F. P. Pullar. 



The September issue of the American Journal of Science 

 contains, as frontispiece, a process portrait of Prof. J. 

 Willard Gibbs, and an obituary notice of Prof. Gibbs by 

 Prof. H. A. Bumstead. The number also contains an 

 article by Mr. J. Stanley Gardiner, of Cambridge, on " The 

 Origin of Coral Reefs as shown by the Maldives." 



The September issue of the Popular Science Monthly 

 (New York) is full of interesting matter, and contains, 

 among other contributions, articles on " Palm and Sole 

 Impressions and their use for Purposes of Personal Identifi- 

 cation," by Prof. H. H. Wilder; " Theories of Sleep," by 

 Dr. P. G. Stiles; "Mosquitoes and Suggestions for their 

 Extermination," by W. L. Underwood; and part iv. of a 

 series of articles by Prof. J. A. Fleming, F.R.S., on 

 " Hertzian Wave Wireless Telegraphy." 



-Messrs. Watts and Co. have issued, for the Rationalist 

 Pjtss Association, a reprint, at si.xpence, of the first edition 

 of " The Origin of Species." It will be remembered that 

 an edition of the final form of this great classic was brought 

 out not long ago by Mr. Murray in paper covers at one 

 shilling. 



The additions to the Zoological Society's Gardens during 

 the past week include a Sooty Mangabey (Cercocebus fuli- 

 ginosus) from West Africa, presented by Mr. C. Pells ; 

 two .Masai Ostriches (Struthio camelus, var. massaicus) 

 from East Africa, presented by Mr. A. Marsden ; two Grey- 

 breasted Parrakeets (Myopsittacus monachus) from Monte 

 Video, presented by Mr. C. Martin; a Vervet Monkey 

 (Cercopithecus lalandii) from South Africa, two Mozambique 

 Monkeys {Cercopithecus pygerythrus) from East Africa, a 

 Black-striped Wallaby (Macropus dorsalis), a Black-tailed 

 Wallaby {Macropus walabates), a Rufous Hare Wallaby 

 {Lagorchestes hirsutus) from New South Wales, two Black- 

 headed Caiques {Caia melanocephala) from Demerara, an 

 Australian Barn Owl {Strix delicatula), a Winking Owl 

 {Ninox connivens), a Burton's Lizard {Lialis burtoni), a 

 Limbless Lizard {Pygopus lepidopus) from Australia,' a 

 Javan Loris {Nycticebus jqvanicus) from Java, two Grey 

 Monitors {Varanus griseus) from North Africa, two Muri- 

 cated Lizards {Amphibolurus muricatus) from Australia, 

 deposited. 



OUR ASTRONOMICAL COLUMN. 

 Search-ephemeris for Comet 1896 v. (Giacobim) — Herr 

 M. Ebell contributes to No. 3898 of the Astronomische 

 Nachnchten a second portion of the ephemeris for comet 

 1896 v. which he commenced in No. 3881 of the same 

 journal. This ephemeris takes as the time of perihelion 

 June 22 5, 1903, but Herr Ebell also gives ephemerides in 

 which the time of perihelion passage is taken as June 6c 

 and Julv 85 respectively. ' 



Efhe 



\2h. M.T. {Berlin). T= June 225 190J. 



log r 



o 2492 



02604 



• 3 54 51 



+ 14 12-2 



+ 13 297 



-f- 12 450 



+ 11 590 



+ 11 12-2 ... 02717 



+ 10 24 9 



+ 9 J7-8 ... 0-2831 



+ 8 51-4 



+ 8 6-5 ... 0-2943 



NO. 



1768, VOL. 68] 



00177 

 .. o on 1 



- 9-9973 

 . . o 0076 

 .. o 0130 



Bright- 

 ness. 

 . 266 



. 261 



. 2 64 



239 



2 21 



Intensity of Spectral Lines. — Circular No. 72 of the 

 Harvard College Observatory is devoted to the explanation 

 of a scheme, proposed by Prof. Pickering, for the form- 

 ation of a uniform universal method of recording the 

 absolute intensities of spectral lines. 



Comparative intensities are easily determined, in the case 

 of bright lines by the bolometric method, in the case of 

 dark lines by using the bright background as the standard 

 unity intensity. Absolute values, however, are much more 

 difficult to determine, and two methods offered themselves 

 to Prof. Pickering's choice. First, the determination once 

 for all of the intensities of certain well-known lines ; 

 secondly, the construction of an artificial standard with 

 which ail lines might be directly compared ; he decided to 

 use the second method. 



A standard scale was constructed in which each line was 

 1-26 times as wide as the one next below it, so that the 

 logarithms of their widths diff'ered by o i, and the scale 

 was then reduced rather more than twenty times and printed 

 on sensitised paper, the haziness, which is characteristic of 

 real spectral lines, being produced by inserting various 

 thicknesses of white paper between the negative and the 

 sensitive paper. 



To standardise this prepared scale the line E of the 

 Fraunhofer spectrum on Higgs's charts was used, and the 

 intensities of thirty-six lines between X 5261-8 and A. 52762 

 were measured, on the scale, on five different charts, and 

 the five independent scale readings, their mean, the 

 residuals from the mean and the width of each line in 

 Angstrom units, are given in the table accompanying Prof. 

 Pickering's paper. 



A Provisional Catalogue of Variable Stars. — No. 3 

 vol. xlviii. of the Harvard College Observatory Annals is 

 devoted to a provisional catalogue of variable stars in which 

 reference is made to some 1227 different variables. The cata- 

 logue has been prepared from a card-index of variable stars, 

 commenced by Prof. W. M. Reed in 1888, and carried for- 

 ward by Miss A. J. Cannon since 1900, which now contains 

 about 34,000 cards referring to observations of variables. 



A new notation has been adopted after grave consideration 

 in this catalogue. Each star is designated by a number 

 containing six figures, which are printed in ordinary type 

 if the star is in the northern hemisphere and in italics if 

 it is in the southern. The first two figures give the hours 

 and the second two the minutes in the R..\., whilst the 

 last two give the degrees in the declination ; thus the 

 designation of the first star in the catalogue (V. Sculptoris) 

 is ooojjg which, when translated, gives the approximate 

 position of the star as R.A.=oh. 3m., Dec. = —39°. 



The catalogue also gives the Chandler number, the name 

 of the star or its constellation, the D.M. number, the exact 

 position for 1900, the chief particulars of the elements, the 

 class of the variable and of its spectrum, and the date of 

 discovery, with the name of the discoverer, for each 

 variable. 



Mass of Mercury. — In No. 3897 of the Astronomische 

 Nachrichten, Prof. T. J. J. See, of Washington, gives the 

 results of his recomputation of the mass of Mercury, and 

 points out, en passant, the importance to workers in 

 celestial mechanics of obtaining the truest possible value 

 of this constant. 



The latest measurements of the planet's diameter have 

 slightly increased the former values, and Prof. See adopts 

 6" 00 as the most probable value of the diameter at unit 

 distance; this gives an absolute- diameter of 4351 ± 72km. 

 and a resulting mass of 171 = 1:148685481743427, which 

 Prof. See adopts as the definite value. The mean specific 

 gravity of the planet, with this mass, is 3 09, and this 

 conforms very well with the other densities obtaining in 

 the solar system. 



Corrections to Existing Star Catalogues. — Since the 

 publication of the " Catalogue of Reference Stars in the 

 Zone +46° to +55°," by the Royal Observatory of Catania, 

 Signor G. Boccardi has discovered a number of errors in 

 various existing catalogues. These are set forth and their 

 corrections given in « paper communicated by him to No. 

 3898 of the Astronomische Nachrichten ; they include errata 

 in the coordinates and in the precessional corrections. 



Twelve catalogues are dealt with, including, amone 

 others,' " The Radcliffe Catalogue of 6317 Stars (18450),' 



