394 



NA TURE 



[February 22, 1906 



Two other types of solids in addition to those 

 already mentioned are susceptible of mathematical 

 treatment, namely, the solids derived by the rotation 

 11I a circle round an axis not passing through its centre. 

 When the axis does not cut the circle a ring with a 

 circular section is produced, such as an ordinary 

 finger ring, which is open at the middle. When the 

 axis cuts the circle, a solid, which Lindemann calls 

 .1 " Wulst " or roll, and resembles in form an 

 orange or an apple- -is generated. A particle having 

 the first of these shapes, when rendered luminous, 

 would, according to the mathematical theory, give 

 rise to lines having wave-lengths dependent on four 

 numbers, to each of which a series of values can be 

 given. The kind of spectrum which results can best 

 be explained by imagining the spectrum due to a 

 luminous particle of the elongated ellipsoidal type to 

 be displaced several times in succession, the relative 

 position of the lines being slightly modified in each 

 shift. Such a spectrum has already been found to 

 characterise oxygen and helium; the oxygen spec- 

 trum, indeed, according to Runge and Paschen. 

 appears as if derived from that of an alkali metal 

 by a series of successive displacements. An atom of 

 the second type, with a shape similar to that of an 

 apple, when rendered luminous, would, according to 

 the calculations, give rise to a spectrum such as 

 would be produced by successive displacements of the 

 lines due to a flattened ellipsoid. The spectra of 

 sulphur and selenium seem, indeed, to be of this 

 type, being derived from a spectrum like that of 

 oxygen by substituting single strong lines for certain 

 groups of lines. The atom of oxygen thus appears to 

 have the form of an open ring, the atom of sulphur 

 or selenium that of a " Wulst." 



Certain interesting consequences concerning tin 

 chemical properties of the elements follow from a 

 consideration of their shape, and have been developed 

 by Prof. Lindemann. That the ring-shaped oxygen 

 atom, for example, is a dyad with regard to hydrogen 

 at once follows from the plate-like shape of the 

 hydrogen atoms, two of these being necessary to close 

 the two apertures of the ring. A distinction, more- 

 over, such as is actually found to exist, is introduced 

 at the outset between valency with regard to hydrogen 

 and valency with regard to oxvgen. Apart from 

 speculations of this kind, Prof, von Lindemann 's 

 work has great significance at the present moment, 

 in that it demonstrates the possibility to derive those 

 physical constants which most clearly define and 

 characterise the individual elements from the concep- 

 tion of a single kind of matter merely by introducing 

 the idea of shape. It is, of course, possible that tin 

 atoms do not possess strictly, but only approximately, 

 the simple shapes which can be treated mathe- 

 matically. If this were so, slight changes would be 

 introduced into the transcendental equations, and the 

 deduced values, for example those in the table given, 

 can be considered only as a first approximation ; but 

 the approximation is sufficiently close to justify the 

 belief that the general type of the transcendental 

 equations is correct. W. A. D. 



THE TIME OF FRANCE. 

 A NOTE from the Paris correspondent of a daily 

 ■**■ journal stating (hat the proposal to adopt 

 Greenwich time in France is again being brought 

 forward, a desirable reform which would bring our 

 nearest neighbour into harmonv in this respect with 

 almost the whole of Europe, may be considered a suffi- 

 cient reason for giving some facts on the subject under 

 discussion. 



Without going back to the earliest proposals for 



NO. 1895, v OL. 73] 



establishing a time-system which should be common to 

 the whole world, an early stage in the movement was 

 the calling of a conference by the Government of the 

 United States to be held at Washington in October, 

 1S84. At this meeting, which was attended by re- 

 presentatives of twenty-five nations, but who, it 

 must be remembered, had no power to bind 

 their Governments to any plan of action, it was 

 resolved that " the Conference proposes to the 

 Governments here represented, the adoption of the 

 meridian passing through the centre of the 

 transit instrument at the Observatory of Greenwich 

 as the initial meridian for longitude." This resolu- 

 tion was voted for by representatives of twenty-two 

 countries, one representative took the opposite view, 

 and two countries, of whom France was one, abstained 

 from voting. 



Following on this, a resolution was passed at the 

 meeting adopting the principle of a universal dav 

 which should begin at mean midnight of the initial 

 meridian, a scheme containing the germ of the present 

 hourly zone system. But a more practical step had 

 already been taken by the managers of the American 

 railways, who, in November, 1883, had adopted the 

 now well-known system in which the American con- 

 tinent is divided into five zones, the time used in each 

 of which is respectively 4, 5, 6, 7, and 8 hours slow- 

 on Greenwich. It says much for the breadth of view 

 of the American railway managers, who thus rose 

 above all consideration of national feeling and selected 

 a zero which was likely to suit the convenience of the 

 greatest number, and set an example which must have 

 done much to forward the scheme. 



Since 1884 there has been no open international in- 

 tercourse on the subject, but gradually the zone time 

 system has made its way. In 1892 Belgium and Hol- 

 land began to use Greenwich time ; in 1893 mid-Euro- 

 pean time, one hour fast on Greenwich, was made the 

 legal standard time in Germany and Italy ; in the next 

 year the same time was adopted in Switzerland and 

 Denmark, and in 1S95 in Norway. Mid-European 

 time had already been in use in Sweden many years, 

 and on the Austrian, Hungarian, Servian, and Mace- 

 donian railways since 1891, but, strangely enough, 

 Vienna, the home of Dr. Schram, who was one of the 

 leaders of the movement for the unification of time, 

 has not adopted any legal standard time. The meri- 

 dian of Pulkowa happens to be 2 hours 1 minute 

 east of Greenwich, and since the time of this meridian 

 is used for telegraph work and on the railways of 

 Russia, it may be considered that this country uses 

 east European time, two hours fast on Greenwich, 

 which is also used for some purposes in Turkey. Since 

 Greenwich time was made the legal time of Spain 

 in 1900, it will be seen that almost the whole of Europe 

 has fallen in line. France has not held aloof for want 

 of consideration of its merits. In 1896 the proposition 

 that the Greenwich meridian should be adopted in 

 France was brought by M. Deville before the Chamber 

 of Deputies, and beiiiL;- voted on was accepted by that 

 body, but the matter went no further, the reason for 

 which mav be inferred from the proceedings at the 

 meeting of the Astronomical Society of France held on 

 December 2, 1S96. At that meeting several of the 

 leading scientific men of France were present, and 

 among them M. Bouquet de la Grye, who. after ex- 

 pressing his astonishment that scientific men had not 

 been consulted before such a proposition was made, 

 proceeded to raise objections. It was true, said he, 

 that the meridian of Greenwich had been chosen as 

 initial because of the greatness of England's sea- 

 power; but, he asked, how long would this continue? 

 England's supremacy in this respect might pass away 

 just as had that of other nations, and what then? 



