AucustT 28, 1902 | 
NATURE 
425 
Zeitschrift f. Elektrochemie, They point out that no trustworthy 
details of the method employed in the various works where the 
metal is now produced have hitherto been made public. Using 
asmall experimental fusion cell, and the ordinary lighting supply 
current of the Karlsruhe Technical Institute, they were able to 
reduce alumina without difficulty and to obtain as much as 
230 grams of the metal in one operation. The metal obtained 
was remarkably pure, one sample tested containing only ‘o5 per 
cent. C and ‘034 per cent. Si. The mechanical tests made 
with six samples of the aluminium gave an average tensile 
strength of 21,425 lb. per square inch. The fused mixture 
used in the carbon cell contained 33 per cent. AIF, 33 per 
cent. NaF and 33 per cent, Al,O3, the high percentage of 
aluminium fluoride being conducive to fluidity. The current 
density employed was about 2800 amperes per square foot, and 
the E.M.F. varied between 7 and 10 volts, The authors, as the 
result of their experiments, have come to the conclusion that 
the steady improvement in the efficiency of the process as carried 
out in the aluminium works is due, not to secret modifications 
in the process, but to the more careful attention now given to 
the purity of the raw materials employed. They also point out 
that the carbon contained in the aluminium obtained in their 
experiments was not present in the combined form, and as it 
was graphitic in character they assume that it represented 
mechanically enclosed particles, due to the disintegration of the 
anode and kathode carbon. By remelting the aluminium, it was 
possible to remove a portion of this impurity from the metal. 
The necessity of employing carbons comparatively free from ash 
is insisted on, since any impurities of the carbon used will be 
found in the final product. 
The additions to the Zoological Society’s Gardens during the 
past week includea Vervet Monkey (Cercopithecus lalandit) from 
South Africa, presented by Mr. J. S. Sweetman ; a Ring-tailed 
Lemur (Zemur catta) from Madagascar, presented by Colonel 
Ewart ; a Tiger (Fe//s ¢7grzs) from India, presented by Mr. A. 
Forbes ; two Two-spotted Paradoxures (Madinia binotata) from 
West Africa, presented respectively by Major D'Arcy Anderson 
and Mr. Walter O’Brien ; two @ank Voles (Arvécola pratensis) 
British, presented by Mr. G. T. Rope; a Broad-fronted 
Crocodile (Osteoloemus tetraspis) from West Africa, presented by 
Dr. W. F. Macfarlane ; a White-collared Mangabey (Cercocebus 
collaris) from West Africa, a Black-faced Spider Monkey (A/e/es 
ater) from Eastern Peru, a White-fronted Capuchin (Cebus 
albifrons) from South America, a Common Marmoset (Hafale 
jacchus), a Six-banded Armadillo (Dasypus sexcinctus) from 
Brazil, a Vulpine Phalanger (Zrichosurus vulpecula) from 
Australia, two Petz’s Conures (Conurus canicularis) from 
Mexico, a Western Boa (Soa occidentalis) from Argentina, 
deposited ; five American Pochards (Fuligula americana) from 
North America, received in exchange. 
OUR ASTRONOMICAL COLUMN. 
ASTRONOMICAL OCCURRENCES IN SEPTEMBER :— 
Sept. 3. 7h. 59m. Minimum of Algol (8 Persei). 
6. Sh im to 1th. 43m. Transit of Jupiter’s Sat. 
13. ub 28m. to 15h. 11m. Transit of Jupiter’s Sat. 
15. Venus. Illuminated portion of disc = 0'945, 
of Mars = 0948. 
22. gh. 2m. to gh. 25m. Moon occults 8! Tauri 
(mag. 4'0). 
22, gh. 14m, to 10h. 2m. Moon occults 8? Tauri 
(mag. 4°7). 
23. Sh. 13m. to 13h. 6m. Transit of Jupiter’s Sat. IV. 
23. gh. 41m. Minimum of Algol (8 Persei). 
NO. 1713, VOL. 66] 
1oh. 34m. to 11h. 12m. Moon occults 115 Tauri 
(mag. 5°4). 
23. 12h.om. Sun enters Libra. Autumn commences. 
23. 13h. 28m. to 13h. 53m. Moon occults 120 Tauri 
(mag. 5°3). 
24. 17h.om. Mercury at greatest elongation (26° 11’ E.). 
24. 17h. 32m. to 18h. 38m. Moon occults 26 Gemi- 
norum (mag, 5 I). 
25. 13h. 40m. to 14h. 4om. 
norum (mag. 50). 
26. 6h. 30m. Minimum of Algol (8 Persei). 
27. 15h. 22m. to 15h. 38m. Moon occults w Leonis 
(mag. 5°6). 
NEw DISCOVERIES OF VARIABLE VELOCITIES IN LINE OF 
SicHT.—In addition to the thirty-two binaries previously 
announced, Prof. Campbell records the data of six more spectro- 
scopic binaries which have been detected with the Mills 
spectrograph ; they are the following :— 
p Persez: a=th. 37m. 35 = + 50° 11’. The maximum varia- 
tion as yet recorded is from +24 km. (December 16, 1900) to 
—12 km. (November 11, 1901). This star has bright hydrogen 
lines, Hy appearing as a narrow absorption line with very bright 
borders. 
n Geminorum: a= 6h. 09m.; 5= + 22° 33’. Maximum 
variation as yet recorded is from +14 km, (January 15, 1900) 
to 25 km. (February 2, 1902). 
y Canis Minoris: a=7h. 23m.; 5= + 9° 08’. Range of 
variability as yet detected is from+40 km. (November 6, 1901) 
to +54 km. (December 22, 1901). 
¢ Herculis : a=16h. 38m. ; 5=31° 47’. This is a well-known 
visual binary having a period of about thirty-three years, but 
the earlier observations of Belopolsky, Campbell and Newall in 
1893, 1898 and 1897-99, respectively, did not establish the 
variability. However, by taking the means of these early 
observations and comparing them with the mean of the recently 
observed velocities determined at the Lick Observatory, it is 
found that the velocity has changed by about 4 km. since 1898. 
a Lquueli: a= 2th. 11m. ; 8 =+4° 50’. The velocity of 
this star varied from — 26 km. on June 25, 1900, to— 2 km. on 
June 25, 1901, and then returned to — 26 km. on June 2, 1902. 
0 Andromedae: a = 22h, 57m. ; 5 = + 41° 47’. The range 
of variability, so far as it is yet known, is from — 11 km. 
(October 9, 1900) to — 20 km. (June 25, 1901). 
Miss Maury, of the Harvard College Observatory, has dis- 
covered the composite character of the spectra of the two last- 
mentioned stars. 
Out of the 350 stars observed up to date, 41 have proved to 
be spectroscopic binaries, giving a proportion of one binary to 
every eight stars observed, not taking into account a number of 
suspected cases which await confirmation, 
The variable velocity of the sun has a double amplitude of 
only a few hundredths of a kilometre, and Prof. Campbell sug- 
gests that, with increased accuracy in our methods of observa- 
tion, we shall probably find that there is a regular gradation 
from this comparatively minute quantity upto the much 
greater velocities already recorded, and that it will be found 
that a star which is xo¢ a spectroscopic binary is a rare excep- 
tion (Lick Observatory Bud/etin, No. 20). 
Sept. 23. 
Moon occults 68 Gemi- 
THE NAMING OF NEw VARIABLE Stars.—No. 3808 of 
the Astronomische Nachrichten contains a list.of the titles which 
have been assigned to the 24 variables discovered during the 
years 1900, 1901 and 1902 by the commission appointed to this 
duty. Among the 24 there are only four variables of the Algol 
type, one of which has the remarkable period of 31-3 days. 
The published table gives the star’s number in Chandler’s 
catalogue, its temporary name, the assigned permanent name, 
the maximum and minimum’ magnitudes, and the data regard- 
ing the position for 1900. 
THE SPECTRUM OF Nova PeErseEI.—Prof. Campbell and 
Mr. Wright subscribe a short note to the Lick Observatory 
Bulletin, No. 20, on the later spectrum of Nova Persei (1901). 
Spectrograms, obtained throughout the autumn and winter, 
up to January 7, 1902, showed no appreciable difference from the 
immediately preceding ones, the fine dark H (calcium) line re- 
ferred to in Sudletin No. 8 ‘still remaining visible. It was 
suggested that the corresponding K dine did not appear “because 
there was no light in that region of the spectrum for the calcium 
vapour to absorb, Lut this suggestion has been. proved incorrect 
