tio 



NA TV RE 



[June i, 1905 



been published by Messrs. C. Arthur Pearson, Ltd. Dr. 

 Lankester has made important additions to his book de- 

 scriptive of the compound microscope and its accessories, 

 and has incorporated a chapter by Mr. F. Kitton on the 

 polariscope and its uses. Dr. John Matthews has edited 

 the second book, and has made several alterations and 

 additions, among the latter being a prefatory chapter deal- 

 ing with preliminary histological manipulation. 



The Bulletin de la SociHi des Nattiralistcs de Moscou 

 (1904, Nos. 2 and 3) contains the following papers : — 

 .Four notes on the crystalline forms and optical properties 

 of various salts. — On the theory of endosaprophytism with 

 lichens, by A. Elenkin. A defence of the latter as ag-ainst 

 the mutualistic theory, with a bibliography of the literature 

 of the subject (in German). — The Jurassic corals of the 

 Sudagh, by A. Missuna (with plates). In a total of 108 

 species, 46 are new for the Crimea, and 14 new species are 

 described. The Crimean coral-fauna has its nearest relative 

 in the Jurassic fauna of Switzerland (this paper is in 

 German). — Materials for the algology of Lake Baikal, by 

 V. Dorogostaisky (with a plate). Results of a two years' 

 study of the algae in Lake Baikal and its affluents. A list 

 of 350 species is given, a few of them being new (this 

 paper is in French). — History of development of the excre 

 tory system with the Amphibiae, D. P. Filatow (in German, 

 with a plate). — The same number contains a fine portrait 

 of Prof. T. A. Bredikhin, and a biographical sketch of the 

 late Moscow astronomer, including a sketch of his theory 

 of comet tails, by P. K. Sternberg. 



OUR ASTRONOMICAL COLUMN. 



Astronomical Occurrences in June: — 



June 2. Venus at ma.\imum brilliancy. 

 „ II. I3h. 3m. Minimum of Algol (8 Persei). 

 ,, 12. 8h. 22m. to 9h. 24m. Moon occults /- Virginis 



(m.ag. 4-9). 

 ,, 13. Saturn. Outer major axis of outer ring = 4o"'87; 



outer minor axis of outer ring = 6"*03. 

 ,, ,, 9h. Mars in conjunction with moon, Mars 6° 14' S. 

 „ 14. 9h. 52ni. Minimum of Algol (/3 Persei). 

 „ 15. Venus. Illuminated portion of disc = 0'365 ; of Mars 



= 0-938. 

 „ 21. I5h. Sun enters Cancer, Summer commences. 

 ,, „ 22h. Saturn in conjunction with Moon, Saturn 



1° 29' S. 

 ,, 23. 23h. Uranus in opposition to the Sun. 

 .,, 27. I4h. 48m. to i6h. 33m. Transit of Jupiter's Satel- 

 lite III. (Ganymede). 

 ,, 29. I4h. lom. to I5h. im. Moon occults 0- Tauri 



(mag. 3-6). 

 ,, ,, I4h 15™. to I4h. 56m. Moon occults 6' Tauri 



(mag. 3-9). 



A Remarkable Variable Star. — In a note published in 

 No. 4017 of the Astronomische Nachrichten Prof. E. C. 

 Pickering states that the light-changes of the variable star 

 154428, R Coronje Borealis, are unlike those of any other 

 known variable. A series of observations, made iDy Mr. 

 Leon Campbell, showed that during the period March- 

 September, 1903, the magnitude underwent remarkable 

 changes between the limits 60 and 9-4. Since then until 

 March of the present year it remained stationary at 

 60 m. The unusual character of the changes during April 

 and May is shown in the following table ; — • 



April 



Observations with large telescopes are now desirable in 

 order to see whether or not this object disappears entirely. 

 NO. 1857, VOL. 72] 



It is easily recognised on the Harvard " Map of the Sky," 

 plate No. 18 (118-75), a"d is nearly equidistant from y. S, 

 and e Corona. 



Radial Velocities of Thirty-one Stars.— For the past 

 ten years line-of-sight observations have been made at the 

 Emerson McMilliri Observatory (Columbus, Ohio), but 

 Prof. Lord has now arrived at the conclusion that, as so 

 many better equipped observatories, situated in more 

 favourable atmospheres, are engaged in this work, 

 it seems advisable to discontinue the observations there and 

 direct the available resources into some other channel 

 of research for which they are better equipped. Con- 

 sequently he has collected all the results obtained during 

 the decennary, and has published them in No. 4, vol. xxi., 

 of the Astrophysical Journal. Complete catalogues of the 

 plates taken and of the standard lines employed, and the 

 collected results, are embodied in his communication. 

 Amongst the thirty-one stars dealt with there occur 

 a, Cassiopeiae, Aldebaran, a. Arietis, o Persei, Capella, 

 Pollux, Dubhe, Arcturus, /3 and 7 Cygni, and B Cephei. 



Magnitudes of Nova Persei and Nova Geminorum. — In 

 No. 4017 of the .istronomische Nachrichten Prof. A. A. 

 Nijland publishes the results of a number of magnitude 

 observations of Novae Persei and Geminorum. The observ- 

 ations of the former covered the period November 15, 1901, 

 to January 13, 1905, and the figures given show frequent 

 increases of brightness, which were, however, very small. 

 A gradual decrease of magnitude underlies these minor 

 fluctuations, and on January 13 the Nova was of magnitude 

 1074. 



The Nova Geminorum observations extended over the 

 period March 27, 1903, to December 30, 1904, and on the 

 latter date the magnitude recorded was 133, more than 

 27 magnitudes fainter than Nova Persei on the same date. 



Oxford University Observatory. — Prof. Turner's re- 

 port of the work done at the Oxford University Observatory 

 during the twelve months ended April 30 informs us that 

 the Oxford work in connection with the International Astro- 

 graphic Catalogue is at last within measurable distance of 

 publication. The measures and reductions were completed 

 last year, and the whole thing is now ready to print. 

 What is still more satisfactory, the university has set aside 

 looo/. for this purpose, and this is to be supplemented by 

 a similar contribution from H.M. Government. 



The stereo-comparator has been used to compare some 

 of the newer with some of the older plates, but, so far, 

 nothing of importance has been discovered ; more time will 

 be given to this work when the coming eclipse is past and 

 the Oxford contribution to the International Catalogue is 

 safely in the press. As some of the earlier plates for the 

 catalogue are less satisfactory than the later ones, they are 

 being duplicated, and the new ones are being measured and 

 reduced as opportunity occurs. An expedition from the 

 observatory, comprised of Prof. Turner and Mr. Bellamy, 

 will observe the total solar eclipse of August next in Egypt. 



Variations of L.4TITUDE. — The provisional results of the 

 work accomplished by the International Latitude Service 

 during 1904 arc given by Prof. T. Albrecht in No. 4017 

 of the Astronomische Nachrichten. The results obtained 

 at the six stations employed in the service are grouped, 

 and the variation of the momentary from the mean pole 

 during the years 1900-4 is graphically shown. From this 

 curve it appears that the year 1904 was marked by a 

 diminution in the amplitude of the variation. 



New Refraction Tables. — Appendix ii., vol. iv. (second 

 series), of the Publications of the U.S. Observatory con- 

 tains a number of reduction tables for transit-circle observ- 

 ations compiled under the direction of Prof. Eichelberger. 

 All of them, except the refraction tables, are of no use at 

 any other observatory, but these may be found useful by 

 other transit observers. They consist of nine separate 

 tables, in which the logarithms of the various arguments 

 necessary for determining the exact refraction correction 

 for each minute of apparent zenith distance from 0° to 

 85° are given. An example which precedes the tables 

 clearly illustrates the method of using them. The tables 

 are based upon those of Pulkowa. 



