November ii, 19 15] 



NATURE 



305 



ly, as being constituted of a potential motion plus 

 ; circulation, is in the present paper applied to a stream 

 |f finite depth. — K. Terazawa : Deep-sea water waves 

 msed by a local disturbance on or beneath the surface, 

 lalytical investigations of sea-water waves produced 

 ^y a local disturbance on the surface have been made 

 various writers. Prof. H. Lamb's paper (Proc. 

 )nd. Math. Soc, (2) II., p. 371, 1904), on the subject 

 the most concise and comprehensive. The earlier 

 irt of this paper consists of an extension of his in- 

 jstigations, and discusses the cases where the initial 

 Jrescribed displacement of the surface or impulse ap- 

 Slied to it is of the form Acosj?i6/ct, where ra is dis- 

 mce from origin, instead of being condensed in a 

 Joint. The displacement of the surface is expressed 

 ^s a power series of ^i^/w, with zonal or associated 

 irmonic functions as its coefficients. As to the 

 jquence of events at the centre of the initial disturb- 

 ance, there has hitherto been little examination. In 

 lis paper that point is discussed, the initial disturbance 

 »ing assumed to be of the form A/\/(b^4CT '), and it 

 found that for this type there occur only a few 

 ises and falls of the surface which cease in a short 

 fJBme. The latter part of the paper is devoted to the 

 problem of the tidal wave caused in deep water by a 

 submarine explosion having its source situated at a 

 }X)int or along a horizontal line, assuming this source 

 to be placed so deep, or its force to be so gentle, that 

 the surface of the water is not broken by the ejection 

 of a water-column. — W. G. DuflBeld : The consumption 

 of carbon in the electric arc. Experiments have been 

 carried out to determine the amount of material lost by 

 the poles of a direct-current carbon arc under different 

 conditions of current and arc length. Before beginning 

 the weighings the arc was burnt to shape ; on this 

 account consistent results have been obtained. For a 

 given current the carbon consumption of both "the 

 anode and the kathode increases with the arc lengtfi 

 until a constant value is reached. Using long arcs the 

 consumption per coulomb decreases with increasing 

 current ; the ratio of anode to kathode consumption is 

 about 1-5, increasing slightly with the current. The 

 study of extremelv short arcs leads to the following 

 conclusions : — (i)'The loss of an atom of carbon from 

 the kathode of a very short carbon arc is accompanied 

 by the transfer between the poles of a quantity of 

 electricity equivalent to four electronic charges. (2) In 

 long arcs the loss is due to this essential carbon dis- 

 appearance plus a quantity due to combustion. No. (i) 

 has been found to hold over a range of current 

 strenirths from 2 to 100 amperes. — Hon. R. J. Strutt : 

 Observations on the fluorescence and resonance of 

 sodium vapour. II.- — J. G. Leathern : Some applica- 

 tions of con formal transformation to problems in 

 hvdrodynamics. Supplementary note. — L. Isserlis : 

 The conditions under which the "probable errors" of 

 frequencv distributions have a real significance. — Prof. 

 W. M. Thornton : The reaction between gas and pole 

 in the electric.il icrnition of gaseous mixtures. ^ — Lieut. - 

 Col. A. G. Hadcock : The longitudinal strength of 

 rvlinders closed by screw plug^s.-^J. G. Leathern ; Some 

 applications of conformnl transformation to problems 

 in hydrodvnamics. — A. B. Wood : Volatilisation of ex- 

 tremely thin radio-active deposits. — S. W. Richardson : 

 Some cxneriments on the properties of dielectrics.— 

 \V. B. Bottomley : a bacterial test for plant-food acces- 

 sories (Anxiiixones). 



Challenger Society, October 27.—Dr. E. J. Allen in 

 the chair. — L. A. Borradalle : The mandibles and asso- 

 ciated structures in prawns. The structures which 

 surround the mouth of the common prawn were de- • 

 scribed, suggestions were made as to their functions, 

 and problems presented by their morphology were dis- 



NO. 2402, VOL. 96"! 



cussed. Reasons were given for believing some at 

 least of the appendages to be derived from limbs of a 

 type which possessed four endites proximal to the 

 endopodite, and one in the region of the ischiopodite. 

 The rest of the endopodite might represent a sixth 

 endite, such as that found on the thoracic limbs of 

 Apui^. 



P.-VRIS. 



Academy of Sciences, November 2.— M. Ed. Perrier in 

 the chair. — The President announced the death of Dr. 

 C. J. Bouchard, member of the academy. — G. 

 Bigourdan : The astronomical work of Fabri de Peiresc. 

 An account of work done between 1604 and 1636. — 

 Paul Vulllemln : The stamens in the Tropeolaceae. The 

 view put forward is the typical arrangement compris- 

 ing three episepal stamens and six epipetal stamens. 

 These do not form a cycle distinct from the corolla. The 

 total number is reduced to eight in the normal flower, 

 because the sixth epipetal stamen and the third episepal 

 stamen form one. — J. liaag : The method of Otto. — P. 

 Zeeman : Fizeau's experiments for different colours of 

 the spectrum. If c is the velocity of liquid in a 

 vacuum, n the refractive index of the fluid in motion, 

 and V the velocity of the fluid relatively to the observer, 

 Fresnel's formula for the resulting velocity is 

 v/n±{i — ifn^)v. Lorentz proposed to replace the co- 

 efficient of displacement, 



(i-i/n^), by i-i/n^-Xjn.dnldX, 

 and the experiments described in the present paper 

 were designed to compare these two coefficients. The 

 arrangement due to Michelson and Morley (1889), 

 slightly modified, was employed, and measurements 

 were carried out with monochromatic light, in which 

 A varied from 4500 to 6870 Angstrom units. The ex- 

 perimental figures were in close accord with those 

 calculated from the Lorentz formula, 

 i_i/n2_A/n.dn/dA. 

 Full details are reserved for a later communication. — 

 Marin IVlolUard : The experimental production of 

 tubercles at the expense of the main stem in the potato. 

 yi. Fleury : The morphology of the massif of Porto-de- 

 Moz (Portugal).— M. Bergenia : The electrical power 

 absorbed by the electro-vibrator. The best conditions 

 of use of this apparatus. — Louis Roule : The migrations 

 of fishes of the family Mugilideae. 



BOOKS RECEIVED. 



The Gases of the Atmosphere and History of their 

 Discovery. By Sir W. Ramsay. Fourth edition. 

 Pp. xiii-l-306. (London : Macmillan and Co., Ltd.) 

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Leeds Universitv. Eleventh Report, 1913-14-15. 

 Pp. 208. (Leeds.) " 



Abridged Scientific Publications from the Research 

 Laboratory of the Eastman Kodak Co., 19 13-14. Pp. 

 76. (Rochester, N.Y. : Eastman Kodak Co.) 



State of Connecticut. State Geological and Natural 

 Historv Survev. Bulletin No. 24 : Triassic Life of the 

 Connecticut Valley. By Prof. R. S. Lull. Pp. 285. 

 (Hartford, Conn.) 



Bartholomew's War Map of Italy and the Balkan 

 States. New edition. (Edinburgh : J. Bartholomew 

 and Co.) is. net. 



A Historical Atlas of Modern Europe from 1789 to 

 1914, with Historical and Explanatory Text. By 

 C. G. Robertson and J. G. Bartholomew. Pp. 244-36 

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 net. 



Annals of the Solar Physics Obsei-vatory, Cam- 

 bridge. Vol. iii., part i. : The Solar Rotation in 

 June, 191 1, from Spectrographic Observations made 



