NATURE 



[February 27, igi^ 



mination of Lines of Position and Geographical Posi- 

 tion at Sea," by Lieut. R. de Aquino, the second 

 edition of which was reviewed in Nature for February 

 6 last (vol. xc, p. 617). 



The proceedings at the conference on the theory of 

 radiation, held in Brussels in 1911, have been referred 

 to in two articles in N.4TURE. The first appeared on 

 November 16, 191 1 (vol. Ixxxviii., p. 82), and the 

 second on January 16, 1913 (vol. xc, p. 545). We 

 have now received a copy of a volume containing the 

 papers read at the conference and reports of the dis- 

 cussions upon them ; it is printed in French, edited 

 b}' MM. P. Langevin and M. de Broglie, and pub- 

 lished by M. Gauthier-Villars, of Paris, at the price 

 of It francs. 



OUR ASTRONOMICAL COLUMN. 



\sTRONO.MICAL OCCURRENCES FOR MaRCH : — 



March 2. oh. 24m. Jupiter in conjunction with the 

 Moon (Jupiter 5° 22' N.). 



3. 22h. 50m. Uranus in conjunction with 



the Moon (Uranus 4° 2' N.). 



4. 8h. 30m. Mars in conjunction with the 



Moon (Mars 3° 19' N.). 

 g. zh. 53m. Mercury in conjunction with 



the Moon (Mercury 1° 29' N.). 

 II. Sh. 30m. Venus in conjunction with the 



Moon (Venus 2° i' N.). 

 13. I2h. 36in. Saturn in conjunction with 



the Moon (Saturn 6° 23' S.). 

 17. 8h. 43m. Neptune in conjunction with 



the Moon (Neptune 5° 34' S.). 



19. 3h. om. Venus at greatest brilliancy. 



20. I7h. i8m. Sun enters Sign of .-\ries, 



Spring commences. 



21. 23h. s8m. Moon eclipsed, invisible at 



Greenwich. 

 29. I4h. 29m. Jupiter in conjunction with 

 the Moon (Jupiter 5° 19' N.). 



The Soi-AR Activity. — A sun-spot of unusually high 

 latitude is at present visible on the solar disc. First 

 SL-en on February 19, when it had just come over the 

 (astern limb in heliographic latitude about 35° N., 

 ihe spot has since developed somewhat, and on Mon- 

 ('.-ly last Ihe leading nucleus was fairly large and 

 tlense. An outbreak in such a high latitude possibly 

 marks the beginning of a new sun-spot cycle, for the 

 new cycles generally commence at a great distance 

 from the equator, while the old cycle is dying away 

 near the equator. 



As pointed out in Monday's Times, the epoch of the 

 nest maximum of spot activity is somewhat uncertain 

 because the previous maximum, 1906, was late, and 

 presented a double peak. 



PHOTOGR.'iPHic Magnitudes ok .Stars in Coma 

 Berenices. — On five plates taken with a 4-in. anastig- 

 mat portrait lens, Herr Hnatek has measured the 

 extra-focal images of 104 stars in the asterism Coma 

 Berenices, and publishes the results in No. 4629 of 

 the Astronomische Nachrichten. In addition to the 

 definitive mean magnitudes, ranging from 52 to 10-3, 

 Herr Hnatek gives the magnitudes as determined 

 from each of his five plates, the B.D. number, the 

 spectral type (Harvard), and the differences between 

 his own and five other measures by various observers ; 

 these comparisons show differences varying with mag- 

 nitude and spectral type. For example, it is seen 

 that the diffr-r.^nce of magnitude Hnatek-Pickering 

 NO. 2261, VOL. 90] 



increases as the temperatures decrease, and amounts 

 to 043 mag. for class K stars. 



The Distribution of Spectroscopic Binary Stars. 

 — From Prof. Stroobant we have received an abstract 

 from the Comptcs rciidus (vol. clvi., p. 37), in which 

 he has discussed the distribution of spectroscopic 

 binaries, as compared with other stars, in the celestial 

 sphere. Dividing the sphere into 20° zones of galactic 

 latitude, he fin^s that of the 306 stars given in Camp- 

 bell's second catalogue of spectroscopic binaries, 217 

 lie within the zone +30° to —30° galactic latitude, 

 and only eighty-nine without it. For naked-eye stars 

 generally, the proportion is 3154 to 2565, according to 

 Houzeau. 



This preponderance near the Milky Way is found 

 to be due to the relatively large number of helium. 

 stars among the binaries, about 35 per cent, of the, 

 total, for, according to Pickering, 93 per cent, of 686 

 helium stars are to be found in the galactic zone. 



High-level Measurement of Solar Radwtiox. — 

 In No. I, vol. xxxvii., of The Astrophysical Journal 

 Prof. Very discusses the conditions affecting the 

 measures of solar radiation at high levels. Taking 

 measures made up to nearly 30 km., he shows that 

 aqueous vapour, the chief atmospheric absorbent of 

 solar radiations, is still present, in appreciable quan- 

 tities, at these great altitudes ; thus the limits of the 

 aqueous atmosphere are extended much further than 

 some meteorologists have thought to be possible. 

 Having reduced observations made at sea-level, 4420 

 and 13,700 metres, he finds thermal equivalents, at 

 these heights, of 1-5, 2-00, and 2-86 cal./sq. cm. min. 

 respectively, and by plotting these results gets a value 

 for the solar constant of radiation of 3-5 cal./sq. cm. 



THE BLEACHING OF FLOUR.^ 



E.'\RL1ER reports to the Local Government Board 

 on the chemical changes produced in flour by 

 bleaching, which have been summarised already in 

 these columns, have been written with the object of 

 producing chemical evidence of the supposed 

 injurious effect of bleaching. A recent legal decision 

 of considerable moment has stated that the presence 

 of 3'43 parts of nitrites per million does not alter the 

 genuineness of flour, and that it is admitted that no 

 injurious effects from such a quantity of nitrites can 

 be proved. The result of commercial bleaching is 

 merely to alter the colour of flour to suit the taste 

 of the consumer without altering the nature, sub- 

 stance, and quality of the flour so as to render it a 

 different article. 



In the present report, Dr. Monier-Williams admits 

 evidence which brings his views more into line with 

 those prevailin^j elsewhere. 



Following the suggestion of Wesener and Teller, 

 the colouring matter of flour has been compared by 

 him with carrotene, the yellow plastid colouring matter 

 of plants which is so obvious in the carrot. The 

 method of comparison adopted is a physical one, 

 namely the examination of the absorption spectra of 

 the two pigments, which are shown to be identical. 

 The colouring matter of flour is thus established as 

 carrotene. 



Pure carrotene crystallises in small leaflets of an 

 intense red colour, which, on exposure to the air, 

 gradually absorb oxygen and form a colourless com- 

 pound. Carrotene also absorbs practically its own 

 j weight of nitrogen peroxide, forming colourless com- 

 pounds of unknown nature, which, however, all give 



1 Report to the Locnl Government Board by Dr. G. W. Monier Williams. 

 Food Reports, No. 19. October, 1912. Price 3^. - - 



