May 9, 1901] 



NA TURE 



45 



prove disastrous to the district if the matter is continually 

 neglected." The district is at present remarkably deficient in 

 opportunities for higher education. With a population approach- 

 ing half a million within easy reach of the centre, there is no 

 institution where young people who have left the secondary 

 school can obtain higher instruction nearer than Manchester 

 (thirty-seven miles) or Birmingham (forty-five miles). Evidently 

 there is room for further provision of educational facilities by 

 the establishment of an institution of the rank of a University 

 College ; and it is satisfactory to know that another locality is 

 being aroused to a sense of its educational deficiencies. 



SCIENTIFIC SERIAL. 



Btilldin of the American Malhemaliial Society, April, igoi. 

 — Prof. F. N. Cole opens with an account of the proceedings at 

 the February meeting of the Society in New York City, and, 

 in addition to the titles of the nineteen papers communicated, 

 gives an abstract of several of them. Three of the papers are 

 printed. Their titles are : (i) Green's functions in space of one 

 dimension, by Prof. M. Bocher. The results arrived at are 

 given, but the proofs and further developments are reserved ; 

 (2) Possible triply asymptotic systems of surfaces, by Dr. L. P. 

 Eisenhart. This supplements a note by the author, in the 

 January j5«/A'//h, entitled, " .\ demonstration of the impossibility 

 of a triply asymptotic system of surfaces. " Instead of the general 

 negadon previously given, the author now gives the qualified 

 one : The only triple systems of surfaces cutting mutually in 

 the real asymptotic lines of these surfaces are composed of 

 properly associated families of hyperboloids of one sheet and 

 hyperbolic paraboloids ; (3) Note on Hamilton's determination 

 of irrational numbers, by Dr. H. E. Hawkes. The purpose of 

 the note is to call attention to Hamilton's use of the partition 

 (Schnitt) in his definition of certain irrational numbers { Trans. 

 of the R. Irish Academy, vol. xvii. 1837, p. 293). — On a system 

 of plane curves having factorable parallels, by Dr. V. Snyder, 

 was read before the December meeting of the Society. The 

 type of scrolls contained in a linear congruence, and having fac- 

 torable asymptotic lines, gives rise to a class of plane curves 

 whose parallels have a similar property (cf. a paper by the 

 author, in the American Journal 0/ Mathematics, vol. xxiii., 

 on a special form of annular surface). Mr. Bromwich gives 

 a very useful analysis of Dr. P. Muth's " Theorie und An- 

 wendung der Elementartheiler " '(1S99, xvi. and 236 pp.), 

 and hopes that the book may induce its readers to take up the 

 special part of invariant theory treated in it. Mr. Bromwich 

 has done good work in this direction (see Proc. of London 

 Math. Soc. vol. xxxii. 1900, p. 98), where he gives a list of 

 papers on the subject. — Short notices follow of Dr. R. Fricke's 

 " Kurrgefasste Vorlesungen liber Verschiedene Gebiete der 

 hoheren Matheniatik, mil Beriichsichtigung der Anwendungen" 

 (1900), and Dr. R. Biiger's " Ebene Cieometrie der Lage " 

 (1900), both by Prof. H. S. White. — The notes are very copious 

 and interesting, giving account of the courses of lectures in the 

 Continental and home Universities, and the usual new publica- 

 tions close the number. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, February 28. — " A Preliminary Account of 

 the Development of the Free-swimming Nauplius of Leptodora 

 hyalitia (Lillj.)." By Ernest Warren, D.Sc. Communicated 

 by Prof. Weldon, F.R.S. 



March 14. — "On the Preparation of Large Quantities of 

 Tellurium." By Edward Matthey, A. R. S.M. Communicated 

 by Sir George Stokes, Bart., F.R.S. 



March 28. — " On the Enhanced Lines in the Spectrum of 

 the Chromosphere." By Sir Norman Lockyer, K.C.B., F.R.S., 

 and F. E. Baxandall, A.R.C.S. 



In the recently published account (Ast. Phys. Journ, vol. xii. 

 p. 307, 1900) of the spectroscopic results obt.iined by members 

 of the expedition from the Yerkes Observatory during the solar 

 eclipse of May 28, 1900, Prof. Frost claims to have established 

 a close relationship between the bright lines in his eclipse spectra 

 and the stronger lines of the Fraunhofer spectrum, and states 

 that "61 per cent, of the latter were measured as bright on the 

 plates." 



NO. 1645, YOL. 64] 



He also states that " these plates give no evidence of any 

 relationship between the bright lines and the ' enhanced ' lines, 

 or lines distinctly more intense in the spark than in the arc 

 spectrum, although .Sir Norman Lockyer has attached much 

 significance to a supposed connection between them." He 

 quotes specially the cases of titanium and iron lines, and of 

 48 enhanced lines of the former element acknowledges that 

 29 — or 60 per cent. — correspond with lines in his eclipse 

 spectra 



The authors of the present paper show that if a difference of 

 o'5 tenth-metres be allowed between the wave-length of .an 

 eclipse line and that of the corresponding metallic line (and in 

 some cases Prof. Frost accepts a difference of 0'35 or more 

 between his adopted wave-length and Rowland's wave-length 

 of the corresponding Fraunhofer line), there are 38 of the 48 

 enhanced titanium lines — or 80 per cent. — which have corre- 

 sponding lines in the eclipse spectra, thus showing a closer 

 relationship between the enhanced lines of titanium and the 

 eclipse lines than that claimed by Prof. Frost between the latter 

 and the stronger of the Fraunhofer lines. 



To show the difference in behaviour in the eclipse spectra of 

 the enhanced and unenhanced lines, several tables have been 

 compiled. The first contains all the Fraunhofer lines in the 

 regi<m covered by Frost's eclipse spectra which have an intensity 

 of 2 or greater, and which Rowland has ascribed to titanium 

 only. These are 53 in number, 20 are enhanced lines and 33 are 

 not. The comparison table indicates that 19 of the 20 enhanced 

 lines have corresponding lines (nearly all prominent) in the 

 eclipse spectra, the remaining one being probably masked by 

 H7. Of the T)}, unenhanced lines, 23 — or 70 per cent. — do not 

 correspond with eclipse lines. Of the nine eclipse lines which 

 do agree in position with unenhanced titanium lines, three are 

 nearly certainly due to other metals, and the remainder are lines 

 of insignificant intensity. 



The second table gives the enhanced lines of titanium which 

 are recorded by Hasselberg in the arc spectrum, and a comparison 

 is made with Frost's eclipse lines. This table shows that though 

 the ** arc " intensities of the enhanced lines vary from 2 to 7 

 (max. = 8), they have nearly all corresponding lines in the eclipse 

 spectra, the majority of the latter being quite prominent. 



The third table contains all the strongest lines (Int. 7 and 8) 

 in Hasselberg's list of arc lines w'hich are unenhanced. It is 

 shown that only 7 out of 20 have corresponding eclipse lines. 

 To three of these Frost gives no origin, to the others he gives 

 compound origins, three of them involving titanium. In no 

 case is the eclipse line as strong as the majority of those which 

 are the representatives of the enhanced lines. 



In the case of iron a similar analysis is given, but only over a 

 limited region of the spectrum (\ 4500 to K 4600) owning to the 

 great number of lines in the iron spectrum. The same results 

 are arrived at, viz., that the enhanced lines, though insignificant 

 in the iron spectrum so far as intrinsic intensity is concerned, 

 are, in the main, represented in the eclipse spectra by lines of 

 abnormal intensity, whereas many of the stronger iron lines are 

 either not represented at all, or only by weak lines. 



" On the Arc Spectrum of Vanadium." By Sir Norman 

 Lockyer, K.C.B., F.R.S., and F. E. Baxandall, A.R.C.S. 



In this paper the authors give a list of lines in the arc spec- 

 trum of vanadium which have been measured from photographs 

 taken at Kensington with a Rowland concave grating of 2li 

 feet focus and 14,438 lines to the inch. The region of the 

 spectrum investigated extends from A 3S87 to \ 4932. The 

 sources of the spectrum were (I) vanadium chloride, and (2) a 

 pure sample of vanadium oxide supplied by Sir Henry Roscoe. 

 These were volatilised in the arc between poles of the purest 

 silver obtainable, and which were furnished by Sir W. C. 

 Roberts-Austen. 



The lines are compared with those published previously by 

 Rowland {Ast. Phys. Journ. vol. vii. p. 273, 189S) and Hassel- 

 berg {Svensha- Vetenskaps. Akad. Handl. vol. xxxii. No. 2, 

 1899). The three records contain many lines in common, but 

 there are also many differences between any two of them. The 

 lines special to any one list have been analysed with the object 

 of either properly establishing their claim to be accepted as true 

 vanadium lines, or possibly tracing them to their true origin. 

 Lines in the Kensington spectra which are due to impurities 

 have been eliminated, as far as possible, by comparing the 

 vanadium spectrum directly with those of forty-three other 

 elements. 'They are twenty-nine in number, and are traces of 

 the strongest lines only of Fe,Mn, Cr, Co, Ca, Al, Sr and Ag. 



