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NA TURE 



[April 15, 1922 



According to a brief despatch from Valdivia 

 published in the Times of April 6, great volcanic 

 eruptions occurred in southern Chile, to the south- 

 east of Puerto Montt, and close to the Argentine 

 border. They were accompanied by violent earth- 

 quakes. Much damage was caused to grazing lands 

 on the Argentine side of the frontier, which for 

 thirty leagues was covered with volcanic ashes. 



We learn from Science that a meeting to initiate 

 the Gorgas Foundation Memorial, founded in memory 

 of the late Maj.-Gen. W. C. Gorgas, who accomplished 

 noteworthy work in connection with tropical diseases 

 in Panama, was held at Birmingham, Alabama, on 

 March 4 last. Among the speakers was the British 

 ambassador, Sir Auckland Geddes, who said : " The 

 name Gorgas will live long after the peoples of earth 

 have forgotten the heroes of the world's greatest 

 war." 



At the annual general meeting of the Chemical 

 Society held at Burlington House on March 30, the 

 following new members of council were declared 

 elected : Vice-Presidents, who have filled the of&ce 

 of President : Prof. H. B. Dixon and Prof. P. F. 

 Frankland ; Vice-Presidents, who have not filled the 

 office of President : Prof. E. C. C. Baly and Prof. 



T. M. Lowry ; Ordinary Members of Council : Dr. 

 C. Doree, Dr. J. J. Fox, Prof. I. M. Heilbron Prof. 

 J, W. McBain, Dr. W. H. Mills and Prof. J R. 

 Partington. 



Under its new constitution the Association of 

 Assistants in Pathological and Bacteriological Labora- 

 tories is now admitting, as associate members,, 

 laboratory assistants from laboratories other than 

 those of pathology and bacteriology. The organisa- 

 tion was founded in 19 12, its chief object being to 

 improve the status of the laboratory assistant by 

 endeavouring to raise the standard of technical 

 knowledge through the medium of an educational 

 programme, culminating in an examination and the 

 granting of a certificate of proficiency in laboratory 

 technique. An official organ. The Laboratory Journal, 

 is issued to members quarterly, and, in addition 

 to Association news, the journal contains original 

 articles and abstracts of technical interest to labora- 

 tory workers ; there is also an employment bureau. 

 From the first the founders had in mind the inclusion 

 ultimately of all laboratory assistants in one federa- 

 tion, and it is hoped that the present movement 

 will lead to the formation of sections embracing 

 other branches of science. The Honorary Associate 

 Secretary is Mr. F. C. Padley, 2 Eldon Place, Reading, 

 from whom further information may be obtained. 



Our Astronomical Column. 



Evening Stars. — After sunset the sky now presents 

 some interesting . planets for observation. At the 

 middle of April Venus will be brilliantly displayed 

 in the western sky, and sets about an hour and a half 

 after the sun has gone down. Jupiter will be visible 

 in the south-east sky and will pass the meridian at 

 an altitude of about 35° soon after 11 p.m. Saturn 

 crosses the meridian 35 minutes before Jupiter, as it 

 is situated 9° westwards. 



Mars will not be visible in the early hours, but rises 

 at midnight at the middle of the month, and will 

 remain visible throughout the morning hours. 

 Jupiter and Saturn may now be very successfully 

 observed in telescopes, as they reach a fairly good 

 altitude, but Mars is very low in Scorpio and only 

 15° above the horizon when due south. The latter 

 planet will continue so far south during the ensuing 

 summer that its markings will scarcely admit of 

 satisfactory investigation by European observers. 

 When the planet is nearest to the earth on June 18 

 next, it will be only 42 millions of miles distant 

 from us, but its greatest altitude will not exceed 12°. 

 In such circumstances good definition of delicate 

 features is almost impossible when high magnifying 

 powers are employed on telescopes. 



The Distances of the Short-Period Cepheid 

 Variables. — Bull. No. 8 of the Astr. Inst, of the 

 Netherlands contains an important research on this 

 subject by J. C. Kapteyn and P. J. van Rhijn. They 

 note that the Cepheids may be divided into two classes 

 with periods greater and less than 16 hours. Ex- 

 cluding those in clusters, there are 39 and 94 stars 

 belonging to these classes respectively ; the first class 

 shows no galactic concentration, while the second 



NO. 2737, VOL. 109] 



shows it strongly, an argument for the relative prox- 

 imity of the former. Provisional proper motions are 

 deduced for 14 of these stars, chiefly from astrographic 

 plates with a time-interval of some 25 years. The 

 mean parallax deduced is 0-0065", while the mean 

 magnitude is 10-3 ; the parallax is 7-6 times as great 

 as that given by Shapley's formula'. It is pointed out 

 that Schouten reached in 191 8 the same factor 7-6 

 for Shapley's parallaxes of the clusters ; lie based 

 this on the assumption that the luminosity curve for 

 the stars in the clusters is identical with that found 

 for the stars as a whole. It should be observed that 

 neither method affects the relative distances of the 

 clusters investigated by Shapley ; it simply divides 

 all of them by a factor. Further, the Cepheid method 

 was only one of several used by Shapley in deducing 

 his distances ; hence it appears somewhat unlikely 

 that they need division by so large a factor as 7-6. 



Kapteyn and van Rhijn also reinvestigate tlie n:iean 

 parallax of the long-period Cepheids, obtaining 0-0029" 

 from 17 stars, of mean magnitude 5-32, which is in 

 good agreement with Shapley's 0-0034" from 11 stars. 

 They express the hope that trustworthy proper 

 motions for all the 39 short-period Cepheids will be 

 available in a few years, and ask for a suspension of 

 final judgment on the distances of the clusters till 

 that time. 



Dr. Shapley gives some evidence on the other side 

 in Harvard Coll. Observ. Bull. No. 765. He states 

 that the light curves of several short-period Cepheids 

 in the Small Magellanic cloud (mean period 0-64 days) 

 give a mean median magnitude 16- 1, closely agreeing 

 with the value 16-2 predicted by his curve. He 

 claims that this supports his previous estimate of the 

 absolute magnitude of these stars. 



