August i, 1901] 



NA TURE 



343 



brightei), and a line in the yellow which recent measures show 

 to be 1)3. 



The strong lines in the green at W 4924, 5019, 5169 and 

 5317, which occurred in the earlier photographs and which were 

 ascribed to iron, are either absent from the later photographs or 

 appear only as very weak lines. 



It has been noted that the lines 447, 501 and D3 appear to 

 vary with the magnitude of the star, becoming relatively more 

 prominent towards a minimum. 



The continuous spectrum has been described throughout as 

 " weak " or " very weak." 



On the evening of April 25 Messrs. Fowler and Butler made 

 comparisons of the Nova spectrum with the spectra of hydrogen, 

 helium, and that furnished by an air spark between poles of 

 iron and zinc. For this purpose a Hilger tw'O-prism star spectro- 

 scope was used with the loinch refractor. The hydrogen line 

 F and the helium line D3 were found to be sensibly coincident 

 with Nova lines. The middle of the strong green line, pre- 

 viously mentioned as A 501, practically coincided with the nitro- 

 gen line 50057, and therefore there is little doubt that it is 

 identical with the chief nebular lineA5007'6. This line was 

 also compared with the asterium line at \ 5oi5'7, but was found 

 to be decidedly non-coincident with it, though of sufficient 

 breadth to nearly reach it. 



Photographic Spectniin. — In so far as the number and posi- 

 tions of the lines are concerned, the few photographs available 

 for discussion were obtained in the early part of the period dealt 

 with in the present paper (March 26 to May 7), and show a 





UrGHT CURVE OF H 



'/3 



(30-incfi refCecCor). 



spectrum very similar to that of March 25, which was described 

 in detail in the last paper. The chief lines shown in the photo- 

 graphs are H3, H7, H5, He and Hf, together with 4471 and 

 4650. 



Characteristics of Hj8. — In continuation of the series of light 

 curves of Hj8 reproduced in the last paper. I give those plotted 

 by Mr. Baxandali from the later photographs. 



It will be seen that the line Hj8 still shows two ma.Kima of 

 intensity. As recorded in the previous paper, the less re- 

 frangible component gave indications of becoming brighter than 

 the more refrangible member. These further photographs 

 indicate that by April 4 the less refrangible had become twice 

 as intense. 



".Total Eclipse of the Sun, May 28, 1900. — Account of 

 the Observations made by the Solar Physics Observatory 

 Eclipse Expedition and the Officers and Men of H.M.S. 

 Theseus at Santa Pola, Spain." By Sir Norman Lockyer, 

 K.C.B , F.R.S. 



The Report gives details as to the erection of coronagraphs, 

 prismatic cameras and other instruments, and of the results 

 obtained by their use during the eclipse, which was observed 

 under very favourable circumstances. Some of the more 

 obvious results have already been stated in a Preliminary Report 

 (Koy. Soc. Proc, vol. Ixvii. p. 341), and the following remarks 

 may now be added. 



A comparison of the photographs taken with the coronagraph 

 of 16 feet focus with those taken about two hours earlier in 

 America indicates that while some of the prominences changed 



NO. 1657, VOL. 64] 



greatly in appearance in the interval, no changes were detected 

 in the details of the corona. 



The spectrum of the chromosphere, as photographed with the 

 prismatic cameras, so greatly resembles that of 189S that it has 

 not been considered necessary to make a complete reduction of 

 wave-lengths. The prominences visible during totality had 

 comparatively simple spectra, the greatest number of lines 

 recorded being thirty-six. 



The heights above the photosphere to which many of the 

 vapours can be traced in the photographs are tabulated and 

 compared with the results obtained in 1898 ; the two sets of 

 figures are sufficiently accordant, except in the case of the 

 shorter arcs, the value 475 miles derived for the lowest measur- 

 able vapours in 1898 being represented in 1900 by two strata, 

 one reaching to 700 miles and the other to 270 miles above the 

 photosphere. 



The bright line spectrum of the corona was decidedly less 

 bright than in 189S, and a much smaller number of rings is 

 seen in the photographs. The three brightest rings are at wave- 

 lengths 53037, 4231 '3 and 39S7 o, and it may be noted that 

 these were also the brightest in the eclipses of 1893, 1896 and 

 189S. The conclusion that the different rings do not originate 

 in the same gas, arrived at from a discussion of the photographs 

 of 1S98, has been confirmed. 



A drawing is given to illustrate the fact that while the details 

 of the green coronal ring are seen in the inner corona, they have 

 no apparent relation to the positions of the great streamers or 

 prominences. For an investigation of this nature the photo- 

 graphs taken with the prismatic camera of 20 feet focal length 

 are specially valuable. 



" On the Mathematical Theory of Errors of Judgment, with 

 Special Reference to the Personal Equation." By Kart 

 Pearson, F. R.S. 



Edinburgh. 



Royal Society, July l. — Prof. Chrystal in the chair. — 

 Dr. Thomas Muir communicated a note on a proposition given 

 by Jacobi in his De Deteynii}iaiitibtts fiinctionalibus^ pointing 

 out that the theorem in question was not so general as might at 

 first reading seem to be implied. — Dr. R. H. Traquair read a 

 paper on the distribution of fossil fishes in the Carboniferous- 

 rocks of the Edinburgh district. From a complete classification 

 of the known forms, eighty-four in all, it was shown that the' 

 same genera and species were found in all the estuarine deposits, 

 even though these were separated by marine limestones which 

 contained a totally distinct set of fossil remains. There was no 

 evidence of life zones. The forms were persistent and no evolu- 

 tionary change could be detected. After the Millstone Grit 

 there was no further appearance of the characteristic estuarine 

 forms. — Dr. J. Beard, in a paper on the determination of sex in 

 animal development, argued that the sex of the animal inta 

 which a given ovum developed was determined from the very.r 

 beginning before the act of fertilisation. The argument was 

 supported by an array of facts in embryology, such as the two 

 kinds of oocytes which had been observed in certain animals. 



July 15. — The Rev. Prof. Flint in the chair. — The chairman, 

 made a suitable reference to the sad loss which the Society and. 

 the wider world of science had suffered in the recent death of 

 Prof. Tait, who had been their general secretary for more thaa 

 twenty years. — The following prizes were then presented : the 

 Gunning Victoria Jubilee prize to Dr. T. D. Anderson for his 

 discoveries of new and variable stars ; the Keith prize to Dr. 

 James Burgess, C.I. E., for his paper on the definite integral 



A' r^ 



. ' - 1 e dt with extended tables of values ; and the 5Iak- 



Jo 

 dougall-Brisbane prize to Dr. R. H. Traquair for his report on. 

 fossil fishes collected by the Geological Survey in the Upper 

 Silurian rocks of Scotland. — Mr. C. Tweedie communicated a 

 paper on the general form of the involutive one-one quadric 

 transformation in a plaqe. — In a supplementary report on the 

 fossil fishes from the Silurian rocks of the south of Scotland, 

 Dr. Traquair announced some new- anatomical features which 

 he had discovered in these fish remains. Thus in some speci- 

 mens of Ccelolepid^e, two dark spots were found probably 

 representing the position of the eyes ; and in one specimen of 

 Lasaiiiiis probkmatictis, vertical angulated lines were seen which 

 might very reasonably be regarded as the remains of body 

 muscle. Nearly perfect specimens of Aleleaspis tessctata show 

 this remarkable genus to have close affinity to Ct//:a/<rj//(, having 

 two orbits on the top of the he.ad, a small dorsal fin, and a 



