196 
about 125 full-page plates and an: analytical subject- 
index. 
Messrs. J. WHELDON AND Co., 38 Great Queen 
Street, W.C., have just published No. 76 of the new 
series of their catalogue. It deals with the journals 
and transactions of many scientific societies, and with 
English and foreign literary and scientific periodicals. 
There are also addenda giving particulars of remain- 
ders of books relating to natural history. The cata- 
logue should be of interest and service to many 
students of science. 
Mr. F. Epwarps, High Street, Marylebone, has 
recently circulated a. very interesting illustrated cata- 
logue of autograph letters, manuscripts, and historical 
documents. A section of the catalogue is composed 
of documents relating to the United States, Canada, 
and the West Indies. 
THE two following volumes are in preparation, 
among others, for appearance in the ‘‘ University of 
Chicago Science Series'’ (Cambridge University 
Press) :—‘‘A Factorial Theory of Evolution,’ by 
W. L. Tower, and ‘‘Chemical Signs of Life,”’ by S. 
Tashiro. 
OUR ASTRONOMICAL COLUMN. 
Tue Rapiat VeLocity or $8 Urs#& Majoris.— 
From observations of the radial velocity made 
at Potsdam some years ago it was concluded 
by Ludendorff that $ Urse Majoris was a 
spectroscopic binary with a period of 27-16 days 
and total range of 153 km./sec. Subsequent observa- 
tions made at the Lick Observatory, however, gave a 
range of velocity no greater than that to be expected 
in the determinations for a constant-velocity star of 
type A. Further interest in the question was aroused 
last year by Guthnick and Prager’s observations of 
the star with a photo-electric photometer, from which 
a variation through o-02 mag. in a period of 0:3122 
day was deduced; the Potsdam radial velocity values 
were thought to be consistent with this period. A 
further investigation of the radial velocity, with special 
reference to short-period changes, has since been under- 
taken at Mt. Hamilton (Lick Observatory Bulletin 
No. 284). Thirty-six plates were taken on three 
nights during February, 1916, but, as in the case of 
the earlier photographs, these do not appear to indi- 
cate a variation through any appreciable or depend- 
able range of velocities. Prof. Campbell hopes that 
someone with less observing opportunity and more 
opportunity for computation will make a further effort 
to discover a periodicity of very small amplitude. The 
plates are available for loan to any experienced 
measurer of spectrograms who may have a plan for 
remeasuring them. 
RapiaL Morion 1n Sun-spots.—Mr. Evershed has 
recently reported on some further investigations of the 
radial motion in sun-spots discovered by him in 1909 
(Kodaikanal Observatory Bulletin 51). Improved re- 
sults have been obtained by the use of instruments 
which reduced the times of exposure, and by working 
only under the best conditions as to definition of the 
spot image. It now appears that the radial motion 
displacement may be very unequal at equal distances 
from the umbra, and the two spots investigated showed 
larger displacements on the limb side than on the side 
towards the centre. There is usually an acceleration 
of velocity from the umbra to the outer limits of the 
penumbra, and then a sudden fall to zero, or to a 
lesser speed which diminishes to zero at some distance 
outside the spot. The radial movement may amount 
to as much as 4 km./sec, at one edge of the penumbra 
NO. 2454, VOL. 98] 
NATURE 
[NovEMBER 9, 1916 
for lines of intensity o and 1 in large spots. The 
diminution of the indicated velocity with increased 
intensity, which was found by St. John, and attributed 
by him to differences of effective level, is confirmed by 
the new measures. In opposition to St. John, how- 
ever, no difference was found for enhanced lines of 
iron as compared with the arc lines of like intensity. 
Mr. Evershed further concludes that while movements 
at right angles to the radial motion may occur in 
the penumbrz, rotational movement is not a constant 
feature. 
Wotr-Rayet BANDS IN THE NucLet oF NEBUL#.— 
In continuation of the work of Wright, the nuclei of 
three additional planetary nebula have been found by | 
G. F. Paddock to give the Wolf-Rayet type of spec- 
trum (Lick Observatory Bulletin, No. 284). e 
nucleus of N.G.C. 6826 shows a fairly bright band at 
4686, and a fainter band at 4657, which is not given in 
Campbell’s list of Wolf-Rayet lines. In N.G.C. 418, 
the band 4686 is faintly seen in the nucleus, while that 
at 4650 is fairly bright. Four bright bands were 
found in the nucleus of N.G.C. 40, namely:— 
Wave-length Width Intensity 
4862-2 14 A. Faint. 
4788:3 13 A. Faint. 
4687-4 if sls Fairly strong. 
4652-1 220A. Very strong. 
The band at 4652 is strongest near its violet edge, 
and seems to shade off towards the red. That at 4862 
corresponds to Hg. 
Barnarp’s HicH Prorrer-Morion Star.—Some in- 
teresting details relating to the discovery of the star 
with the largest known proper motion have been given 
by Prof. Barnard (Popular Astronomy, vol. xlvii., 
p- 504). The star was shown on plates taken in 1894, 
1904, 1907, and 1916, and the images were so far 
apart as to seem to represent different objects, which 
might be new or variable stars. It was found, how- 
ever, that all the images were in a straight line, and 
that the different photographs could be reconciled by 
supposing the images to have been made by a star 
with-an annual proper motion of about 10”, in a direc- 
tion almost exactly north. At the epoch 1916-423 the 
R.A. of the star was 17h. 53m. 43-60s., and the declina- 
tion +4° 27! 48"; it was 9-1s. following, and 51” north 
of B.D.+4° 3560. The star is situated in the northern 
part of Ophiuchus, and is of about the roth visual mag- 
nitude. The movement may easily be detected in the 
course of a few months, and photographs and charts 
are given for the benefit of those desiring to observe 
the star. 
Mr. Adams has found that the type of spectrum is 
Mb, and that the star is approaching the earth with a 
velocity of 91 km./sec. The relative intensities of cer- 
tain spectral lines suggest a parallax of 0-2", and it 
would follow from this that the star’s real velocity in 
space is 260 km./sec. 
A CaTALoGuE or MeteoritEes.—An illustrated hand- 
book and descriptive catalogue of the meteorite collec- 
tions in the United States National Museum, prepared 
by Dr. G. P. Merrill, has recently been published by 
the Co oie Office, Washington. Though 
the handbook is intended primarily for the general 
public, it is so arranged as to provide also for the 
needs of the student and investigator. At the begin- 
ning of the present year the collection included 329 
falls and finds, and an equal number of thin sections 
for microscopic study. There is a brief introduction, 
giving an interesting account of the characteristics 
of meteorites, and of the system of classification, fol- 
lowing in the main that proposed by Brezina. In a 
large number of cases the results of analyses are given. — 
