NA TURE 



[May 31, 1906 



in geography. The catalogue includes descriptions of 

 simple instruments for map making and other field work, 

 determination of position, and meteorological observations. 



In the notice of " Oologia Universalis Palsearctica " in 

 Nature of May 24 (p. 79) reference was made to the 

 shortcomings of the English text. Messrs. Williams and 

 Norgate ask us to state that arrangements have been 

 made with Mr. Oliver G. Pike to revise the English text, 

 so that in future the work may not suffer from imperfec- 

 tions of expression due to poor translation. 



The " Statesman's Year-book " (Macmillan, price 

 los. 6ii. net) continues to grow in size and value. The 

 1906 issue is some 150 pages larger than its immediate 

 predecessor. Separate notices of the States included in the 

 American union have this year been introduced for the 

 first time. Recent important events have led to other 

 changes in the year-book, and among these' may be men- 

 tioned the dissolution of the union between Sweden and 

 Norway, the peace between Russia and Japan, the mission 

 to Tibet, and the last general election. The maps and 

 diagrams, which are always an attractive feature of the 

 publication, this year deal with the economic development 

 of the United States, the new provinces of Canada, the 

 division of Bengal, the Anglo-Portuguese Barotse boundary, 

 the political changes in the Far East, the races of Russia, 

 and the tariff chart of the world. The volume now runs 

 to Ixiv+1604 pages. The editor. Dr. J. Scott Keltic, is to 

 be congratulated upon the forty-third issue of this indis- 

 pensable work of reference. 



OUR ASTRONOMICAL COLUMN. 



Astronomical Occurrences in June : — 

 June 2. I5h. Conjunction of Venus and Neptune. (Venus 

 2° 24' N.). 

 7. loh. 45m. to iih. 51m. Moon occults m Sagittarii 



(mag. 4-0). 

 10. 3h. Jupiter in conjunction with the Sun. 

 „ I3h. 43m. to I4h. 46m. Moon occults i Capricornii. 



(mag. 4-3). 

 12. iSh. Saturn in conjunction with the Moon. Saturn 



0° 56' N.). 

 15. Venus. Illuminated portion of disc =0-849. Of 



Mars =o'997. 

 i5. loh. 19m. Minimum of Algol (fl Persei). 

 21. 2ih. Sun enters Cancer. Summer commences. 

 24. loh. Venus in conjunction with the Moon. (Venus 



2° 29' N.). 

 26. 5h. 3m. Moon approaches very near to a Leonis 



(Regulus). 

 28. i6h. Uranus in opposition to the Sun. 

 ,, Saturn Outer major axis of outer ring =4i"'47. 

 Outer minor axis of outer ring =2"'3i. 



Photographing the Corona vitithout a Total Eclipse. 

 — Numerous experiments have been devised and carried 

 out in the attempt to obtain photographs of the solar 

 corona during ordinary sunlight, without waiting for the 

 rare occasions on which the sun is totally eclipsed. 

 Hitherto no decided success has rewarded these efforts, 

 but another attempt is to be made by MM. Millochau and 

 Stefanik with an equipment mounted on the summit of 

 Mont Blanc. 



These observers propose to employ a spectroheliograph 

 such as is now used at several solar physics observ- 

 atories to obtain monochromatic images of the chromo- 

 spheric clouds and prominences, but, instead of using one 

 of the calcium or hydrogen lines on the second slit, they 

 propose to isolate the chief corona line, at A. 5303, and to 

 eliminate the light of other radiations by means of an 

 appropriate green screen. 



Preliminary experiments with this apparatus at Meudon 

 NO. 1909, VOL. 74] 



have given encouraging 'results, and the observers hope 

 that, in the clear atmosphere of the mountain summit, 

 indubitable success will be attained (Comptes rcndiis. 

 No. 17, 1906). 



Terrestrial Temperatures and the Solar Radiation. — 

 In the report of the Smithsonian Institution for the year 

 ending June 30, 1905, Mr. C. G. Abbot, who has charge 

 of the Astrophysical Observatory, discusses the recent 

 observations of solar radiation and its connection with 

 terrestrial temperatures. 



This matter was discussed by the late Prof. S. P. 

 Langley in the Astropltysical Journal for June, 1904, who 

 then arrived at the conclusion that the evidence available 

 indicated that the total solar radiation may vary in com- 

 paratively brief periods, and that the irregular variations 

 were frequent and large enough to produce considerable 

 changes of the earth's mean temperature. 



In the present communication Mr. Abbot summarises 

 the results obtained since 1902, and, by comparing the 

 values found for the transmission of the solar envelope, 

 and the consequent transmission of the solar radiations to 

 the earth, with the variations of temperature at a number 

 of stations situated in the terrestrial north temperate zone, 

 he has deduced evidence which strongly supports Prof. 

 Langley 's theory. 



High values of solar radiation and solar transmission 

 appear to precede and to accompany high temperatures in 

 the north temperate zone, and vice versd. 



The tables and curves which appear in the report sub- 

 stantiate this view, and Mr. Abbot expresses the hope that 

 the study of the solar radiation will soon prove a valuable 

 aid in forecasting climate. 



The Distribution of the Stars. — In No. 7 of the 

 Publications of the Groningen Astronomical Laboratory 

 Prof. Kapteyn published the material on which he based 

 his studies on the distribution of the stars in space, the 

 distribution of cosmical velocities, &c., and also gave the 

 results of five separate computations based on three 

 different values of the precession and three different posi- 

 tions of the apex of the solar motion. 



In this publication 2640 stars of Bradley's catalogue were 

 grouped in ten degrees of declination, and the results given 

 in two tables, the first of which contained the stars having 

 spectra of Secchi's second type, the second the stars of 

 type i. and unknown spectra. 



No. 9 of the same publications contains the results of a 

 sixth computation based on more refined data and arranged 

 in a different manner. Instead of grouping the stars 

 according to declination, Prof. Kapteyn has arranged them 

 in zones of Galactic latitude, because, in considering the 

 structure of the universe, it is obviously desirable to take 

 the Milkv Way as the fundamental plane. Also, instead 

 of including the stars having unknown or peculiar spectra 

 with those of type i., he has placed them in a table by 

 themselves. In this way he has discussed the distribution 

 and proper motions of 1093 stars belonging to type ii., 

 1 144 stars belonging to type i.. and 3S1 stars the spectra 

 of which have not yet been recognised as belonging to 

 cither of Secchi's groups. 



The complete catalogue should prove of exceptional 

 interest and usefulness to anyone engaged in any dis- 

 cussion on cosmical evolution, and it would be exceedingly 

 interesting to see what modifications might be necessary 

 if the stars were divided into subgroups according to their 

 ascending and descending temperatures as given in Sir 

 Norman Lockyer's classification. 



Observations of Comets. — The results of a number of 

 observations of various comets, made at the Chamberlin 

 Observatory (Denver) by Prof. H. Howe during the period 

 November, 1004, to June, 1905, appear in No. 4091 of 

 the Astronomische Nachrichten. 



Six comets are included, of which comet 1Q05 i. (Encke) 

 was observed from November 1 1 to December 27, 1904, 

 and at times appeared to have a faint nucleus and an 

 eccentric, fan-shaped tail. At 6h. 20m. (local M.T.) on 

 December 5 a star of mag. 90 shone so lustrously through 

 the comet that the nucleus was invisible. 



Half an hour later the nucleus, which was near the 

 following end of the comet, was plainly visible. 



