460 



NATURE 



[July 3, 19 13 



conductivity and fluidity. He had already shown 

 that, in the case of tetraethylammonium iodide, the 

 product > B x h = const., the values of \ ccand n^ 

 varying sixteen-fold, whilst the product varied only 

 by 2 per cent. Similar experiments are now described 

 with six additional salts, namely N(CH 3 )J, 

 NfCH^.NO..,, N(CH 3 ),,CNS, N(C 3 H n ) 4 I, piperidine 

 picrate, and triamylamine picrate, fourteen organic 

 solvents being used altogether in the different experi- 

 ments. The same remarkable constancy of the pro- 

 duct *co ijco was noticed in every case, whilst the two 

 picrates gave the same constant when the measure- 

 ments were extended to aqueous solutions. 



A set of a new series of Contoured County Hand 

 Maps, issued by Messrs. G. W. Bacon and Co., Ltd., 

 at id. net each, has been received. The maps will 

 be of real service in those schools, fortunately an 

 increasing number, where the teaching of geography 

 is based upon practical exercises worked by the pupils 

 themselves. The maps will make it possible for 

 children to appreciate the importance of the relief of 

 an area in determining its geographical character. 



A compleie catalogue of the books in the Central 

 Lending Library at Coventry is being issued in five 

 parts. The first part, which has been received, is 

 concerned with scientific subjects and various arts. 

 The catalogue is divided into an author and title 

 index, a class list, and a subject-index. The librarians 

 may be congratulated upon a careful piece of work 

 which should prove very useful to readers using the 

 library. 



Particulars of some of the most efficient forms of 

 optical lanterns and accessory apparatus are stated in 

 an illustrated catalogue just published by Messrs. 

 Reynolds and Branson, Ltd., of Leeds. Prominence 

 is "rightly given to the Stroud and Rendell science 

 lanterns, which can be adapted to many purposi -, and 

 are equally useful for the projection of lantern-slides, 

 apparatus, or practical experiments in science teach- 

 ing. The " Rystos " penological micro-polariscope is 

 an instrument designed by Dr. Dwerryhouse to pro- 

 ject upon the screen sections of minerals and rocks 

 as nearly as possible under the conditions in which 

 they are seen under the microscope. The notes given 

 in the catalogue on the arrangement of lantern and 

 accessories for various demonstrations illustrate the 

 flexibilitv of lantern apparatus for purposes of in- 

 struction. 



The Year Book for 1912 of the Carnegie Endow-- 

 ment for International Peace has now been issued. 

 In a letter dated December 14, 1910, addressed to the 

 trustees of the endowment, Mr. Carnegie said : — " I 

 have transferred to you as trustees of the Carnegie 

 Peace Fund, 2,000,000/. of five per cent, first mortgage 

 bonds, the revenue of which is to be administered by 

 you to hasten the abolition of international war, the 

 foulest blot upon our civilisation. Although we no 

 longer eat our fellow-men nor torture prisoner-, nor 

 sack cities, killing their inhabitants, we still kill each 

 other in war like barbarians. Only wild beasts are 

 excusable for doing that in this the twentieth century 

 NO. 2 2 79, VOL. 91] 



in the Christian era, for the crime of war is inherent, 

 since it decides not in favour of the right, but always 

 of the strong." The year-book details the steps which 

 up to the present the trustees have taken to secure 

 the objects aimed at by the fund. The numerous 

 reports — of the executive committee, the secretary, and 

 of the directors of the various divisions into which 

 the work of the trustees is divided — all show that 

 strenuous and successful efforts are being made in 

 many parts of the world to educate peoples in the 

 desirability of abolishing war as a means of settling 

 disputes. 



OUR ASTRONOMICAL COLUMN. 

 A Solar Observatory for New Zealand. — For 

 many years it has been felt that the European and 

 American Solar Physics Observatories should be sup- 

 plemented bv similar observatories in that great stretch 

 of longitude which at present is not represented. The 

 establishment of Kodaikanal was a tremendous ad- 

 vance in the right direction, and a further successful 

 step was taken by the founding of the new observa- 

 tory in Australia ; the latter, we hope, will soon be 

 in active operation. By the generosity of Mr. Thomas 

 Cawthron, of Nelson, New Zealand, this chain of 

 stations will be carried still further east by about 

 25 of longitude, for he has offered to build, equip, 

 and endow a solar observatory in the vicinity of 

 Nelson. The climate of Nelson seems admirablv 

 suited for such a station. The choice of the actual 

 site is, according to a communication from Miss 

 Proctor, in the hands of Sir Robert Ball, who has 

 been requested to send a representative to select that 

 which is most advantageous, and also to give estimates 

 regarding the equipment. Let us hope that this, the 

 " Cawthron Solar Observatorv," will soon be in active 

 operation also, thus completing the girdling of the 

 earth from the solar physics point of view. 



A Curious Aspect of Jupiter's Third Satellite. — 

 J. Guillaume communicates to the Comptes rendus 

 for June 9 an interesting observation relative to the 

 appearance of Ganymede, Jupiter's third satellite, near 

 the end of its transit across the planet. Instead of 

 the regular circular disc which it usually displayed, 

 he noticed on May 24 last that it had a gibbous form, 

 reminding him, as he says, of Mars at the epoch of 

 quadratures, and, furthermore, that it showed a very 

 white north polar spot with a grey zone smaller in the 

 eastern part than in the western'part. These details 

 were more apparent when the satellite was projected 

 on the disc than when off it. M. Guillaume remarks 

 that he has seen this appearance several times in 

 1890 and 1893 with a reflector of 0216 metre aper- 

 ture, but never in such a conspicuous manner as on 

 May 24, when he was using the equatorial coud^ 

 (aperture 0-320 metre) at the Lyons Observatorv. 



The Star Clusters in* Perseus, N.G.C. 869 and 

 8S4. — In vol. ii., No. 2, of the Astronomische Abhand- 

 lungen of the Hamburg Observatorv in Bergedorf, Dr. 

 B. Messow publishes the discussion with the results 

 of the mean positions and brightness of 649 stars in 

 the two clusters in Perseus N.G.C. 869 and '884, after 

 his measures of two photographic plates. The plates 

 were secured on October 3,^1890, by Herren Eberhard 

 and Ludendorff, with the small photographic refrac- 

 tor (34 cm. aperture, 3-4 m. focal length) of the Astro- 

 physical Observatorv at Potsdam, and the exposures 

 lasted five minutes each under good observing condi- 

 tions. 



