94 
A general classification of the phenomena which are thus 
presented under varying conditions is put forward, the grouping 
being as follows :— 
(1) Broadened bright line. Examples of this stage are 
presented in the spectrum of copper and the under- 
exposed spectrum of iron. 
(2) Broadened bright line with central absorption line. Well 
shown in the central line of the violet triplet of iron, 
A 4063°76. 
(3) Broadened bright line with non-symmetrical absorption 
(maximum of emission towards red). A good example 
of this is the iron line at A 4260°64. 
An additional feature of the water-spark spectrum is that 
many of the lines show inversion of intensity with respect to the 
air spark spectrum, This is well shown in the lines of iron at 
AA 4422°74 and 4427°48. 
From these considerations it appears that, if suitable 
exposures are given, lines may be photographed in the spectrum 
of iron, say, which show all the phenomena described by Dr. 
Wilsing, but so related to each other and the complete stage— 
that of reversal, symmetrical or unsymmetrical—that it is 
impossible to regard them as anything abnormal. 
Again, when these appearances are contrasted with the 
structure peculiar to the spectra of Novae, many divergences of 
vital importance are found. 
In the water-spark the position of the absorption undergoes 
little if any change of position, while in the case of non- 
symmetrical reversals, a bright line may be observed greatly 
displaced towards the red. In the newstars, on the other hand, 
the absorption lines are greatly displaced, the accompanying 
> 4065: 76 
*407/:9/ 
bright lines occupying in*comparison normal positions. 
Thus, 
in the case of Nova Aurigze the emission lines had practically 
normal wave-lengths, but the displacements of the dark lines at 
He were about 10°7 tenth-metres towards the violet, indicating a 
velocity of approach of about 500 miles per second. 
recent new star in Perseus exhibited the same normal positions 
of the bright lines, and indications of even greater displace- 
ments of the dark lines, at one time amounting to 15 tenth- 
metres at He, representing a velocity of approach of the body pro- | 
ducing the dark-line spectrum of more than 700 miles per second. 
These values differ enormously from those produced by pressure. 
It appears then that the known direct effect of pressure on 
the radiation or absorption lines is the same, in quality, in 
water as in air, that is, displacements are obtained in the 
opposite direction to those the dark lines are observed to occupy 
in the spectra of Nove ; moreover, the amount of shift observed 
| centre of star photographic images. 
| 
NATURE 
in the spectra of new stars differs, not only in this respect, but | 
also in degree, thus :— 
Spark in water. 
1. Absorption _ lines 
shifted. 
Radiation lines most shifted. 
Absorption shift small. 
New stars. 
least Absorption lines most shifted. 
Radiation lines least shifted. 
Absorption shift enormous. 
wh 
It would thus appear that the pairs of bright and dark lines 
shown in the spectra of new stars do not arise from the cause, 
presumably pressure, which produces the appearances presented 
in the spectrum of the spark discharge in water. 
Royal Astronomical Society, May 9.—Dr. J. W. L. 
Glaisher, president, in the chair.—Mr. H. C. Plummer read a 
paper on the accuracy of photographic measures, in which he 
criticised M. Loewy’s recent memoir on the subject. Mr. 
Plummer doubted the possibility of expressing by a single 
NO. 1699, VOL. 66] 
| 
[May 22, 1902 
formula the probable error of measures of stars on photographs, 
and considered the question of personality in estimating the 
The paper gave rise to 
some discussion, in which Mr. Hinks, Prof. Turner and others 
took part.—Father Cortie read a paper by Father Sidgreaves 
on the spectrum of Nova Persei from September 6, 1901, to 
February 12, 1902, and showed photographs on the screen. 
During the period mentioned, the lines of the spectrum had 
remained very broad and preserved their relative intensities. — 
Father Cortie read a paper on visual and spectroscopic obser- 
vations of the sun-spot group of May and June igor. It 
appeared that the disturbed area of the corona of May 18, as 
shown on the eclipse photographs, corresponded with the region 
in which the spot group had its origin, and marked the time 
of the outburst, though the region had been disturbed quite a 
solar rotation before the birth of the spot. In this case of the 
only great sun-spot in an otherwise quiet year there appeared no 
correspondence between solar storms and terrestrial magnetic 
disturbance. The most widened lines in the red end of the 
spectrum of sun-spots are always faint lines, chiefly of vanadium 
and titanium. The author concluded that the level of sun-spots 
is that of the upper, more diffused gases, which give the flash 
spectrum in solar eclipses. In the discussion which followed, 
doubt was thrown upon the presence of vanadium in the flash 
spectrum.—Mr. Dyson described the Greenwich photographic 
observations of the satellite of Neptune, and also gave an 
| account of a paper by Mr. Cowell ona method of reduction 
of extra-meridian observations. The method was a general one, 
suitable for observations at any azimuth, and the computation 
was facilitated by tables. 
SS4 9° 
Linnean Society, May 1.—Prof. S. H. Vines, F.R.S., 
president, in the chair.—Mr. J. E. Harting exhibited photo- 
graphs of a living specimen of the African shoe-bill (Ba/aenzceps 
| vex), forwarded from Cairo by Sir William Garstin, K.C.M.G., 
The | 
and gave some account of the bird and of the different views 
| which had been expressed by zoologists regarding its affinities 
and systematic position.—On the cerebellum of the lemurs, by Dr. 
Elliot Smith. In this paper, to be published as an addendum to 
that on the cerebrum read on March 6, the author introduces a 
revised terminology. Resolving the cerebellum into three main 
lobes—anticus, medius and posticus, he discards the term 
‘*fissura horizontalis magna,” since the fissure so named is found 
to be inconstant and sometimes absent, and substitutes for 
“preclival” the term /vzma, regarding the fissure thus named, 
which divides the lobus anterius and medius, as the deepest and 
as constant for all mammalian forms. The detailed characters of 
the lemuroid cerebellum are described, and the cerebellum of * 
Notoryctes is incidentally shown to be the simplest for all 
mammals.—On the brain of the elephant shrew (AZacroscedédes 
elephantopus, Shaw), by Dr. Elliot Smith. The brain of 
Macroscelides is shown to be marsupial in the existence ofa 
dorsal fornix commissure of crescentic type, unique in the 
coexistence with this ofa distinct and independent callosum, 
equal in extent to that of the higher Primates. Comparison is 
drawn with the cerebrum of those higher Metatheria in which 
the fusion of callosum and fornix commissure (psalterium) is the 
rule ; and the author concludes that the examination microscopic- 
ally of well-preserved material, of which he is expectant, will 
reveal a connection between these two which may not necessarily 
contain nerve-fibres, and may thus realise a condition he has 
previously described for the Hapalidz.—On the early condition 
| of the shoulder-girdle of the polyprotodont marsupials Dasyurus 
and Perameles, by Dr. R. Broom, The author shows that in the 
mammary feetus of the native cat of Tasmania and Victoria 
