116 
precious stones, and references as to where the pre- 
cious stones of his time came from; ‘ Rings,” Dr. 
G. F. Kunz, illustrated; ‘‘The Art of Anzesthesia,”’ 
Dr. P. J. Flagg, illustrated; and (in ‘* Lippincott’s Farm 
Manuals’) ‘* Productive Sheep Husbandry,” Prof. 
W. C. Coffey, illustrated; “* Productive Marketing of 
Farm Products,’’ A. E. Cance, illustrated; ‘‘ Produc- 
tive Feeding of Farm Animals,” Prof. F. W. Woll, 
new edition, illustrated; ‘‘ Productive Soil Mainten- 
ance,” C. E. Thorne, illustrated; ‘“‘Animal Hus- 
bandry,’’ Prof. C. W. Gay, illustrated; ‘‘ Productive 
Grape Growing,” Prof. B. S. Pickett, illustrated. 
OUR ASTRONOMICAL COLUMN. 
FIREBALL OF OctToBeR 3.—Probably what was the 
most brilliant meteor that has appeared in the present 
year was seen on Tuesday, October 3, at 8.5 p.m. It 
passed over Devonshire, and, though the night was 
cloudy, it gave a very vivid illumination of the sky 
and landscape, and its apparition was witnessed by 
great numbers of persons in the S.W. counties of 
England. 
The observations are, however, not very accurate or 
consistent one with another in consequence of there: 
being very few, if any, stars visible at the time from. 
which its path might be taken. The flight was: ver- 
tical as observed at Bristol, and was similarly de- 
scribed at various stations in Devon and Cornwall, so 
that a radiant at or near the zenith is inferred. At 
Launé¢eston, however, the course is stated to have been 
from E. to W., and the fireball’ burst when near the 
zenith.» Mr. W. F. Denning has determined the real 
path from the data at hand, and places the probable 
radiant'in the head of Cepheus. The height of the 
meteor was about 67 to 30 miles above a’ point’ of 
the earth’s surface some 15 miles E.N-E. of Exeter. 
A few further observations from ‘Dorset or Devon 
would be very valuable as affording a test of the 
accuracy of this result; any such observations should 
be sent to Mr.. Denning, 44 Egerton Road, Bristol. 
Mercury Vistste BerorE Sunrise.—Mercury will be 
a morning star during the latter half of this month, 
and at its greatest western elongation at midnight 
following October 20. The planet will rise from a 
point a little S. of due E, at the following times :— 
Mercury 
Mercury rises Sun rises precedes Sun 
a.m. a.m. h, m. 
Oct. 15 4 51 6 26 135 
17 4 48 6 29 I 41 
19 4 46 6 32 1 46 
21 4 46 6 36 150 
23 450° .... +639 149 
25 4.§8)) Vo. t6lga 144 
247 Si ite GLAG, 1 38 
29 A as dh 7 hea SX 2 NS Rp Bec 
31 ‘ 5 27 GyGget en 5 20 
The waning crescent of the moon will be in the same 
region of Mercury on the morning of October 25. 
Tue DisrriuTion or B Srars.—An important 
memoir on the distances and distribution of the B 
(helium) stars has been published by Prof. Charlier 
(Nova Acta Reg. Soc. Sci., Upsala, series iv., vol. iv., 
No. 7). \It contains all the details which led to the 
general conclusions previously announced (NATURE, 
vol. xevii., p. 369). In a group of stars having the 
same luminosity, the distance (r) of each individual 
star can be deduced from the apparent magnitude (m) 
by the relation r=R.10%* m, where the parameter R is 
the distance for apparent magnitude o-o. A first deter- 
mination of R was based upon the proper motions and 
tadial’ velocities of 156° stars brighter than 5th mag- 
nitude. for which the requisite data were available; 
its value is 4-76 siriometers (1 siriometer=a million 
NO. 2450, VOL. 98] 
NATURE 
[OcTOBER 12, 1916 
times earth’s distance from sun). The corresponding 
absolute magnitude, or apparent magnitude at a dis- 
tance of one siriometer, is given by M=—s log R, and is 
equal to —3:39. It was next discovered that the fainter 
stars gave a somewhat, smaller value of R; and the 
brighter stars a higher value. . This anomaly was 
found to be due to the varying luminosities of the — 
different sub-classes. Separate investigation of these; 
showed, in the main, that types B1 and B2 have the 
greatest luminosity, R being 7:4 sir., whereas types 
Bo, B3, Bs have a value of K=3-3 sir. For each sub- 
class the value of R appears to be independent of 
apparent magnitude. Having the value of R for each 
sub-class, the position in space of each star at once 
follows, and it results that the B stars form a well- 
defined cluster, gradually thinning out from the centre 
to a distance of 200 siriometers. ‘The centre of the 
cluster, which Prof. Charlier supposes to be coincident 
with the centre of the stellar universe, is in R.A. 7-7h., 
declination —55-6°; it lies in a rich region in Carina, at — 
a distance of 18-2 sir. from the sun. The cluster has: 
an extension nearly three times as great in the plane 
of the Milky Way. as in the direction at right angles, 
and the sun lies eccentrically with respect to it, at a 
distance of 4 sir. above the fundamental plane of the 
Milky Way. The mean density amounts to 0-0026 stars 
per cubic siriometer. A catalogue of the 804 known 
B stars is given, showing all the data relating to type, 
magnitude, distance, galactic co-ordinates, and so on. 
The distribution of the stars is further shown diagram- 
matically, and stereoscopic charts are in course of pre- 
paration. It is of interest to note further that the 
nearest B star is a Eridani, with a distance of only 
4 sir. (r=0-0516"), while the three stars in the belt of 
Orion come next, with a distance of 8:sir. So far’as 
they go, direct determinations of parallaxes support the 
values of R used in the investigation. : 
Tue Specrroscopic Binary “x AURIGZ.—An orbit for 
the spectroscopic binary x Aurigz (type Br) has*been 
calculated by R. K. Young from eighty-eight single- 
prism spectrograms taken at Ottawa in the years 
1913-16 (Journ. RsA:S. Canada, vol. x., p. 358). ‘The 
period has the exceptional value, for an early. star, 
of' 655-164 5-26 days; the eccentricity is or71, and the 
orbital velocity 20:53 km./sec. The residuals from the 
simple elliptic orbit were examined for indications of 
the presence of a third body, but no secondary period 
was found; further investigation of this point, with 
high dispersion, is considered desirable. The calcium 
lines (H and K) have an amplitude of about half that 
shown by other lines of the spectrum. A useful»sum= 
mary is given of the different cases of anomalous be- 
haviour of the calcium lines at present known, and — 
Mr. Young considers that the phenomena are best ex- 
plained on the supposition that there is a calcium cloud 
surrounding the binary, the absorption of this sub- 
stance taking place at a much higher level than that 
of the other elements. 
A New AstronomicaL JourNaL.—We have pleasure 
in directing attention to the publication in France of 
a new monthly periodical devoted to astronomy and 
meteorology. It bears the title La Revue Verte, and 
is edited by the Abbé Th. Moreux. The journal is in- 
tended especially for amateurs, and will include articles 
iving practical instruction in methods of observa- 
tion, in addition to general astronomical news, and 
notes on celestial phenomena during each month, In 
the first number there is an article on sun-spots and 
meteorology by the editor, and the firSt of a series of 
articles on variable stars by Prof. Moye. There is also 
a brief biography, with portrait, of M. Baillaud, direc- 
tor of the Paris Observatory. All communications are 
to be addressed to M. |’Abbé Th. Moreux, Observatoire 
de Bourges (Cher), France. The annual subscription 
is 6 francs in France, and 7 francs for other countries. — 
