I lO 



NA TURE 



[July 22, 1909 



■of bananas from the West Indies. A full description of 

 .the vessel appears in the Engineer for July 9, from which 

 we note that she is of 5000 tons gross, having insulated 

 space of 220,000 cubic feet, the capacity of the fruit bins 

 Tjeing 175,000 cubic feet. Granulated cork is used for the 

 insulating material, the average thickness of the cork being 

 ■from 7 inches to S inches, and the bins are so constructed 

 .that the bunches of fruit do not come into contact with 

 metal surfaces during transit, all such being protected by 

 wood gratings and battens, or by hemp-rope coverings. An 

 -elaborate arrangement of air passages enables cooled air 

 to be supplied throughout the cargo, the cooling of the air 

 being effected by a Hall's CO^ refrigerating plant. An 

 fven temperature of 55° F. is maintained, and the fruit 

 is inspected frequently so as to ensure its arrival at Man- 

 chester in proper condition for the market. In loading, the 

 fruit is stored without covering of any kind, the lowest 

 bunches are arranged with stems vertical, and the final 

 layer placed horizontally, an arrangement which economises 

 space and ensures freedom from damage. 



A SECOND edition of Mr. Arturo Massenz's " Lavorazione 

 •e Tempera degli Acciai " has been published by Mr. Ulrico 

 Hoepli, of Milan. The price of the volume is 2 lire. 



Solutions of the exercises in their " Modern Geometry " 

 'have been prepared by Messrs. C. Godfrey and A. W. 

 "Siddons, and are published in volume form by the Cam- 

 bridge University Press at 4s. net. 



Messrs. Dawearn and Ward, Ltd., have published a 

 ■fifth edition of the 1909 " Photographic Annual, in- 

 corporating the Figures, Facts, and Formulse of Photo- 

 graphy." This year-book is edited by Mr. H. Snowden 

 "Ward, and the piesent issue has been extended, largely re- 

 written, and revised to June, 1909. 



Mr. Bernard Quaritch has just issued a catalogue of 

 ■books oil natural history which he is offering for sale. 

 Particulars are given of works on zoology, geology, 

 paleontology, mineralogy, and botany. Among other 

 interesting items we notice the original drawings of 

 Hubner's European butterflies, an example of Jacquin's 

 Selectarum Stirpium Americanarum Historia, and a few 

 imprartant hcrbals. 



We have received in two volumes parts .'\, B, C, and 

 T) of the quarterly bulletin of the results for the year 

 1907-8 secured during the periodical cruises and in inter- 

 mediate periods in connection with the Permanent Inter- 

 ■national Council for the Exploration of the Sea. The 

 parts in order deal with the temperature and salinity of 

 ■the surface water; the temperature, salinity, density, &c., 

 of sea water at different depths ; the oxygen, nitrogen, and 

 ■carbon dioxide dissolved in sea water ; and plankton tables 

 for August and November, 1907, and February and May, 

 1908. The first three parts have been prepared with the 

 assistance of Mr. Martin Knudsen, and the last with the 

 help of Mr. Harry M. Kyle. The volumes are published 

 by Andr. Fred. H0st et Fils, of Copenhagen. 



^ OJJR ASTRONOMICAL COLUMN. 



Stationary Meteor Radiants. — Since Mr. Denning 

 announced the existence of stationary meteoric radiants in 

 1878, many observers have endeavoured to explain, and 

 account for, them, hitherto without much success. The 

 apparent radiant of a meteor depends almost as much on 

 the true direction of the earth's motion as it does on the 

 ^true motion of the meteor itself, therefore it seems almost 

 impossible that these bodies should appear to stream from 

 the sanie point of the heavens for months at a time. In 

 •an article appearing in No. 5, vol. xxix., of the Asiro- 

 phystcal Journal (June, p. 365), Prof. W. H. Pickering 

 NO. 2073, VOL. 81] 



shows, however, that this apparently puzzling phenomenon 

 is only what is to be expected, arguing from our present 

 knowledge of meteor-orbits. Briefly, he shows by diagrams 

 and tables that the attracting force of the earth's mass is, 

 at different times, capable of deflecting or accelerating the 

 smaller bodies, so that the apparent change of the longi- 

 tude of the radiant counterbalances the variation produced 

 by the earth's motion ; thus the radiant appears to be 

 stationary, or nearly so. Prof. Pickering also produces 

 arguments against the prevalent idea that meteors are 

 generally of infinitesimal mass. 



Comparison of the Spectra of the Centre and Edge 

 of the Sun's Disc. — Previous observations having indicated 

 that in passing from the centre to the edge of the sun's 

 disc the spectrum suffers modification, MM. Buisson and 

 Fabry recently repeated the observation, using their inter- 

 ferometer method, in which each wave-length is examined 

 independently of those of the other lines. Their observa- 

 tions, which are published in No. 26 of the Comptes 

 rcndus, confirm the earlier ones of Hale and Adams, and 

 Halm. 



The latter showed that the wave-length of a line in the 

 spectrum at the limb was a little greater than when the 

 centre of the disc was observed. From the study of four- 

 teen lines in the region of X 4400 MM. Buisson and Fabry 

 find that the increase of wave-length varies from 0.004 '° 

 0.006 Angstrom ; to this rule the two vanadium lines, 

 \ 4375-4 and \ 4406-8, are exceptions. The observations 

 also show that in the spectrum at the limb the same lines 

 are a little broader than in the spectrum at the centre, the 

 increase of breadth amounting, in the mean, to o.oio 

 Angstrom. 



MM. Buisson and Fabry suggest that these two pheno- 

 mena, displacement and broadening, are due to the same 

 cause. Tile only modification a line really undergoes is a 

 displacement, amounting to o-oio Angstrom, of its red 

 edge, the more refrangitjle edge remaining invariable. In 

 the exceptional case of vanadium the broadening is 

 apparently symmetrical. They suggest, further, that the 

 asymmetrical broadening may be caused by pressure — an 

 increase of seven atmospheres would be sufficient to pro- 

 duce the observed effect — but only becomes apparent at the 

 limb where a greater thickness of the denser layers is 

 traversed by the radiations. 



Changes of Form tn Sun-spots. — Some interesting results 

 of detailed observations of sun-spot forms are discussed, 

 and illustrated by drawings, by M. A. Amaftounsky in No. 

 43'?2 of the Astronomischn Nachrirhten. 



He shows that whilst, in general, the outline of the 

 penumbra roughly follows the form of the nucleus, tremen- 

 dous changes may take place in the former, whilst the 

 latter is apparently undisturbed. This is what would be 

 expected on the hypothesis that the nucleus of the spot is 

 a depression, n hole, and the penumbra is produced by the 

 ascending and descending of incandescent vapours. The 

 appearance of bright spots in the nucleus, sometimes 

 followed by the bridging and disintegration of the latter, is 

 ext>lained by the supposition that the nucleus is at a 

 higher temperature than the photosphere, and constantly 

 re-vaporises the filaments and tongues of the penumbra by 

 the expulsion of hotter vapours. 



Mutual Occultation of Jupiter's Second and Fourth 

 Satellites. — In No. 4338 of the Astronomisrhe Nachrichten 

 M. Pidoux describes the conjunction and mutual occulta- 

 tion of J ii. and J iv. observed by him at the Geneva 

 Observatory on June 17, 1908. Plotting the various 

 measures, he finds that the conjunction took place at 

 8h. 33.4m. (G.M.T.1, the shortest distance between the 

 centres of the satellites being 1-9". Whilst the latter 

 quantity agrees exactly with that calculated and published 

 by Oudemans, the time is 4.6 minutes in advance of the 

 ephemeris. 



According to calculation, satellites iii. and iv. should 

 have been in conjunction at 7h. "sS.sm. on July 3, 1908. 

 but when first observed by M. Pidoux, at 7h. 52m., the 

 conjunction was already complete and the satellites 

 appeared as one. At 7h. 59m. the system was elongated, 

 and at Sh. 2m. the two images were distinctly separated. 

 It therefore appears that the observations prove the calcu- 

 lated times to be several minutes too late. 



