February 6, r.919] 



NATURE 



459 



ology, .iinl for greater facilities for students 

 desiring to pursue courses of work in applied science; 

 bul there are- likel) to be differences of opinion as to 

 the wisdom of inaugurating a separate university 

 devoted only to stud) and research in pun and applied 

 \i Manchesti i , < dasgow , I Edinburgh, 

 Sheffield, Bristol, and othei places the colleges ol 

 technologj have in recenl years become technical fa'cul- 



of me universities of their respective areas; and 

 ii would seem thai similar co-ordination might be 

 possible in a reconstituted I niversit) of I. mi. Km with 

 the Imperial College and other London colleges which 

 provide special Facilities in applied science, forming a 

 faculty ol technology. Also, ii may be doubted 

 whether the associateship oi the Royal School ol 

 Mines a constituenl college ol the Imperial College 

 could be given a higher value than ii has al presenl 

 bj being merged in a mining degree of the proposed 

 new university. No doubl these matters havi been 

 considered b) the promoters of the movement, and 

 will be carefully weighed by the governors of the 

 Imperial College before taking thi steps suggested. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, January 23. Sir ,|. J. Thomson, 



idi 111, in the chair. Admiral Sir Henry Jackson 



and Prof. G. I>. Bryan: Experiments demonstrating 



an electrical effect in vibrating metals. Experiments 



described which demonstrate the electrical effect 



produced bj vibration in wires and other metallic 



bodies, and a method oi detecting and recording them 



by means of searching coils connected to delicate 



ding apparatus. The diminution of the effect 



when the surface of a steel wire is rusted is dealt 



with, in continuation of a paper by one of the authors 



on the subject of vibrating wires. The inductive effect 



ot a vibrating wire on a neighbouring circuit is men- 



d; and this led up to the fact that all metallic 



experimented with, whatever their shape or 

 material, generate eddy currents, which can be de- j 

 tected in them by usina suitable searching coils. That 

 this effect is primarily due to the vibrating conductor 

 cuttine- the lines of the earth's magnetic field is proved 

 by the experiments, but that the,,' seems to he a 

 residual effect, not at present fully accounted for, 

 which is greatei than 'an be attributed to experi- 

 mental errors Details of the tests are described. 

 These have been carried out with wire bridges, 

 tubes, utensils of various forms and materials, 

 and also with Chladni plates. — Prof. T. fl. 

 Havelock : Wave resistance: son* cases of three- 

 dimensional fluid motion, it is shown how to calculate 

 tlie wave- resistance when the surface- pressure is two- 

 dimensional and the wave-pattern like that of ship- 

 waxes. Certain cases are examined in detail, and the 

 method can he extended to more complex systems. 

 Interpte ting some of the results in let ins of ih, 1 elated 

 problem ol a submerged body, expressions are ob- 

 tained for the wave resistance ol a prolate spheroid 

 anil ol ''Ii-- bodies. W. S. Abell : Chances of loss 

 of merchant ships. This communication discusses the 

 effect ol damag( to vessels in respect < > f chances ot 

 lev, ot bulkheads and the consequent chances oi loss 

 of vessels. If the extent of damage be- fairly con- 

 . as in torpedo explosions, it would appear that 

 there is an inferior limit to tin snaeino of bulkheads. 

 Further, as th< carriage of cargo is impeded by sub- 

 division, there is an economic reason for calculating 

 th> number of bulkheads sufficient for reasonable safe ty, 

 Such calculation involves the- discussion of chances oi 

 loss of one bulkheads, and of the relation ot 



size of vessel to bulkhead spacing. Assuming thai wati r- 

 257I; VOL. 102] 



tightness is destroye 1 within radius R from centre of 

 damage, it is shown that where (1) bulkhead spac- 



ing = 2R + a, the "odds oil" for loss of one bulkhead 

 are 2R <i ; (2) spacing iR a, -'odds on" toi l6ss oi 

 ;,eo bulkheads an- a (2R 20); and (3) spacing^R-a, 

 odds on" for loss of three bulkheads an- 2o/(R jaj. 

 These results an- applied u, the case of ordinary 

 cargo-carrying vessels oi fixe 1 type, hut ol varying 

 lengths, with R = 2o ft. representing longitudinal 

 t of torpedo damage. Diagrams accompanying 

 hat (1) for a given standard ol p sub- 

 division decrease of size of .large vessels only slightly 

 increases chances of loss; (2) for small vessels risk 

 of loss is relatively high, and it is doubtful whether 

 am subdivision whatever is effective for vessels below 

 120-ft. length; (3) safety increases markedly, with 

 length of vessel; and (4) intermediate- bulkheads an- 

 more useful in larger vessels, but may also, ..1 certavn 

 ,.,s,s incase risk of loss. By suitable assumptions 

 the method max be used to discuss subdivision of 

 passenger vessels exposed to ordinary marine risks. 

 Prof W M Hicks : A critical study of spectral sere - 

 Part'v ■ The- spectra of the monatomic gases. ..his 

 part deals with the series relationships in the second 

 or bin,- sp.-ctra of the rare gases. Not only are the 

 S I) and F series allotted, but the discussion serves 

 to' amplify and sustain the laws developed in preceding 

 oarts and illustrates their value for the purpose of 

 ^analysis of spectra in general. Amongst new 

 , ,' thocls may be mentioned th>- us,- of the- links, dis- 

 covered in part iv. of these communications for the 

 purpose of dealing with lines expected from formulae 



, her considerations which lie outside the obs- 

 "Lion Thus, in the case of a wave-number n of a 

 Hr£ in the- ultra-violet n-e, or n-u, or vice versa if 



n the ultra-red « -c. >' + "> where ''• " T * It rh 

 calculable- quantities, may be wave-numbers in the ob- 

 e'ved region and correspond with lines actually seem 

 In this wav it is possible to obtain evidence of the 



is em-; and 'wave-length of lines belonging to he 

 spectrum, although not actually measured Of irn- 



ice'alsointhe eeneral theory of spectra is .1 

 discovery of summation series. Thus in the case t 

 the ordmary well-known series the wave-numbers ate 



„ as the difference of two quantities 



,' ,,„,,. ,„ is the order in the series, ft is 

 show, hat in th,- case „f the F series at leas there 

 are in addition to these difference frequencies, also 

 a cor espond ng series of summation frequences given 

 lynlT+^m). For S, D series such series if 

 listing, would occur far down in the ultra-violet. 



Paris. 

 Uademv of Sciences, January 20. M. L<fon Guignard 

 in th,- chair. II. Deslandres : The- reform of the 

 calendar. A discussion of a recent proposal of M. 

 Hi hu dan with a summah of previous proposals 

 with the same object. A sketch of an alternative 

 \ ' „ , is ,, n , „. 1. \ndrade : The minimum number 

 of associate! spirals. -R. Gamier: The irregular sin- 

 gularities of linear differential equations.— M. «">««'• 

 The analytical prolongation of .he integrals o certain 

 systems of linear partial differential equations.-G. 

 ., uli a-. Som, problems relating to the .tera.on of 

 rational fractions.-P. Levy: Functions of imp! t 

 li nes \ (iuldberg : The errors of situation oi a point. 



\[ ' Mesnatfer : A case of simplification of the formulae 

 ,,f' m. Boussinesq. E. Belot : \ hyp nging 



into agreement the vortex cosmogony and the explana- 

 tion of the Deculiarities of nova- and the sun >.. 

 Dejardin: Calculation of the ratio of the principal 

 soecific heals of benzene and of cvclohexane by the 



yclfo method of M. Leduc. E EscMgon : A nfiw 

 ^termination of the- velocity of sound in the open 



