306 



NA TURE 



[June 27, 1907 



The mean and exlrcnie meteorological values for twenlv- 

 five stations in the British Empire during the year 1905 

 are given in Symons's Meteorological Magazine for May. 

 So far as these stations are concerned, the following high 

 shade temperatures were recorded : — Calcutta, iob°i 

 (June); Madras, io7°q (May); Melbourne and Coolgardie 

 (West Australia), io8°-5 (January) ; Adelaide, i09°-7 

 (January). The lowest readings were : — Fredericton (New 

 Brunswick), —33°.5, Winnipeg, — 39°-i, Dawson, — 50°-5 

 (all in January) ; the latter station had the lowest mean 

 temperature (25°2). Coolgardie had the highest tempera- 

 ture in the sun's rays, i78°-8, the lowest mean humidity, 

 52 per cent., and least rainfall, 7-86 inches. The greatest 

 rainfall, 77-89 inches, was at Grenada, and the dampest 

 station was London, 83 per cent. .Similar valuable tables 

 have been published monthly for more than twenty-five 

 years, but it must be clearly understood that these few 

 widely scattered stations are quite insufficient to give a 

 complete conspectus of the climate of the vast area in- 

 cluded in the British Empire. 



The new method of lighting which h.is recentiv been 

 installed in the courtyard of the Savoy Hotel is creating 

 much interest, and is, we believe, the first installation of 

 this particular system in this country. The system is the 

 result of years of experimenting, and the results are now 

 given by Mr. D. McFarlane Moore in his paper recently 

 read before the American Institution of Electrical 

 Engineers. The chief feature of the system is the auto- 

 matic valve, which admits the exact quantity of air or 

 gas required to prevent the violent spasmodic flickering 

 due to the higher degree of vacuum in the tube causing 

 a higher resistance, and which up to the present has 

 prevented a perfect vacuum-tube lighting being placed on 

 the market. The important points about the valve are its 

 simplicity and its automatic action. The valve admits 

 the air required about once a minute, and by changing 

 the nature of the gas admitted the colour of the light can 

 be arranged as required. The main objection to the system 

 appears to be that a high pressure is required ; consequently 

 each tube must at the ends be led into a transformer. We 

 should also like to know more about the initial cost of 

 the installation, the length of life of the tube, efficiency, 

 &c., than we are told by Mr. Moore in his paper. If the 

 matters mentioned above are satisfactory in comparison 

 with the present costs and eflflciency of modern forms of 

 lighting, the new system should prove of value for large 

 shops, studios, and art galleries, where it is essential to 

 have the lighting as near as possible to daylight. Further 

 developments will be watched with interest, but fuller 

 figures relating to tests will be required before the system 

 can be considered seriouslv. 



From Messrs. Hiiger, Ltd., we have received a copy of 

 their newly published "List A," in which many well- 

 designed spectroscopes and pieces of spectroscopic apparatus 

 are described and illustrated. The Hiiger wave-length 

 spectrometer may now be had fitted with a camera of 

 21 inches focal length at an additional charge of 6/. 10s. 

 Spectroscopists will be interested, too, in the new series 

 of six spectrographs— three of which arc fitted with ultra- 

 violet glass and three with quartz prisms and lenses — 

 especially designed to give, with a short exposure, the 

 whole length of spectrum, in good definition throughout, 

 on a flat plate, and to be in permanent adjustment. The 

 excellent results obtainable with these spectroscopes are 

 illustrated by an enlarged copy of the spectrum of copper 

 extending from K 57.S2 to \ 2160, which we have examined. 

 This was taken w-ith a quartz spectrograph having two 

 NO. 1965, VOL. 76J 



30° prisms and lenses of 8" focus, the distance from 

 A. 6000 to A 2160 on the original negative being 60 mm. 

 (2I"), price 21J. los. The Michelson interferometer, read- 

 ing to one ten-thousandth of a millimetre, is a fine instru- 

 ment at the moderate price of 35/., as is also the Jamin 

 refractometer at 17/. 10s. Messrs. Hiiger also make a 

 speciality of the strips of plane parallel glass for the 

 Lummer and Gehrcke parallel-plate spectroscope. The 

 prices range from 10/. for a plate 100x30x10 mm. to 

 39!. for one measuring 300X40x10 mm. 



" What is Genius? " (" Che cosa k il genio? ") is the 

 title of a small book by .Molfo Padovan (Milan : U. Hoepli, 

 1907, second edition). The author discusses examples of 

 genius among artists, poets, philosophers, and others ; he 

 distinguishes between genius and talent, and strongly 

 advocates the view that genius is to be regarded as a 

 healthy or physiological rather than a morbid or patho- 

 logical quality. In this way he is led to the definition 

 on the cover of the book : "a physiological state of 

 exquisite and exceptional nervous sensibility." 



Dr. Paul and Tatina Ehrenfest revive interest in the 

 statistical problems of the kinetic theory in their paper on 

 two of the objections to Boltzmann's minimum theorem in 

 the Physikalisclw Zeitschrift (May). They deal, first, 

 with Loschmidt's objection, based on the consideration of 

 reversal of the motion, according to which for every 

 possible direct motion there exists a possible reversed 

 motion, and, secondly, with Zermelo's objection, based on 

 the quasi-periodicity of the motion of a system of gas- 

 molecules. The authors claim to h.ave overcome these 

 objections by showing that a state in which Boltzmann's 

 function increases is statistically enormously improbable. 

 It would, however, seem to follow, according to this view, 

 that the existence of irreversible molecular phenomena 

 must be regarded as due to the assumed preexistence of 

 enormously improbable initial conditions. 



Part vi. of " G. A. Fothergill's Sketch Book," which 

 is published by Mr. James Dodds, of Darlington, con- 

 tinues the " History of Cleasby in Yorkshire, with 

 Biography and Portraits of John Rotinson, D.D., The 

 Last Statesman-Bishop (1650 to 1723) ; and numerous 

 Sketches of Rlaekwell Grange and Thornton Hall, 

 Darlington, &c." Some good sketches of sundials are in- 

 cluded in the part before us. 



A LF.CTURE appreciative of the work and influence of the 

 late Mr. Herbert .Spencer, delivered by Prof. August 

 Stadler in the Zurich Tow-n Hall on December 6, iqo6. 

 has been published in pamphlet form by Mr. A. Muller. 

 Zurich. 



DivisiONAL-voLVME ii. of " Practical Coal Mining," the 

 first divisional-volume of which was reviewed in Nature 

 of May 23 (p. 77), has just been published by the Gresham 

 Publishing Co. The volume contains a continuation of 

 section iv., on shaft-sinking, by Prof. Henry Louis; 

 section v., on breaking ground, by Mr. H. F. Bulman ; 

 and section vi., on methods of working and timbering, by 

 Prof. E. H. Robertson. We propose to defer any further 

 notice of the work until the whole of the volumes have 

 been issued. 



We have received from the proprietors of the periodical 

 called the Young Citizen (12 Salisbury Square, B.C.) a 

 case containing twenty-four paper butterflies, pinned and 

 outspread to resemble real specimens. They are, we 

 believe, copied from a well-known work on the subject, 

 and at a considerable distance might pass muster, but we 



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