684 

by Mr. Lewis L. Mellor; and observations of double 
stars discovered at the La Plata Observatory (13th 
Catalogue), by Prof. W. J. Hussey. Numerous 
observations of comets, including comet Daniel 
(1909) and of some minor planets, are also published. 
The preceding part (pp. 1-72) of the volume was 
noticed in NATURE, vol. xci., p. 67, March, 1913. 
OccuLtTaTION oF 8 Scorpit BY JUPITER (1876).—The 
Bulletin of the Astronomical Society of Barcelona 
(vol. iii., No. 6) contains an article by Senor Vicente 
Ventosa, of the Madrid Observatory, describing 
observations he had the good fortune to secure of 
an unpredicted occultation by Jupiter of the brighter 
component of £ Scorpii on February 27, 1876. In 
the Nautical Almanac for 1876 this conjunction was 
given as a very close approach with the star, 0° 1’ N. 
Jupiter was obscured by clouds when the occultation 
commenced, and when observations were possible , 
was invisible and emersion was witnessed. This con- 
junction was referred to in NaTuRE, vol. xiii., p. 188, 
and described by Mr. J. Birmingham in the same 
vol., p. 368. Senor WVentosa, by making use of 
Coniel’s corrections to Bouvard’s tables of Jupiter, 
has calculated the circumstances of the occultation, 
and from his observations of the variation of magni- 
tude of the star as it left the limb obtains a probable 
height of 2500-3000 km. for the Jovian atmosphere. 
An extended account of the research is to be published 
in the Revista of the Royal Academy of Sciences of 
Madrid. 
Tue FiGuRE Or THE EartH.—Many books have been 
written on this subject, yet the current literature is 
so comparatively inaccessible to non-specialists, and 
such meagre statements are generally given in text- 
books, that there must be many persons ready to 
welcome the authoritative essay by Prof. W. de Sitter 
in the August number of The Observatory. In 
directing the attention of our readers to this article, 
we may add that Prof. de Sitter comes to the con- 
clusion that to improve our knowledge of the figure 
of the earth we must observe minor planets, and 
that the opposition of Eros in 1931 will afford the 
earliest opportunity. It will no doubt be recalled that 
last year Prof. E. W. Brown, in his opening address 
to the sub-section of Cosmical Physics of the British 
Association, stated that direct observations of the 
moon’s parallax are likely to furnish at least as 
accurate a value of the earth’s shape as any other 
method. 
METEOROLOGY OF THE Moon.—An_ extremely 
interesting article under this heading appears in 
Popular Astronomy (No. 3, 1915), contributed by 
Prof. William H. Pickering. It is largely the out- 
come of some two and a half years’ observations, for 
which the Jamaican station of the Harvard Observa- 
tory has evidently proved highly satisfactory. Details 
are given of changes observed in selected types of 
lunar surface, elevations, depressions, and level areas. 
The changes are given as being typical of what is 
everywhere taking place. A series of drawings of 
the lunar mountain Pico is reproduced. All the re- 
corded changes are held to fit in with the hypothesis 
of snow or ice formation, or the reverse. The article 
successfully makes obvious that our satellite still 
offers a most fruitful field to zealous and patient 
work. : 
R Corona: Boreatis.—This irregular variable is 
apparently undergoing one of its more or less sudden 
failures of light. Prof. A. A. Nijland (Ast. Nach, 
4809, 184) reports that whilst for 23 years it has been 
constant at about 6-4m., on July 24, as estimated in 
opera-glass, its magnitude was 7-1, and on July 29 
NO. 2390, VOL. 95] 
NATURE 



| AuGUST 19, 1915 

only 7-6. We find that Prof. Nijland observed 
secondary minima during the preceding light fluctua- 
tions on March 8 and May 13, 1912, the star then 
fading to 10-2m. and 8.2m. respectively. 
THE PRETORIA MEETING OF THE SOUTH 
AFRICAN ASSOCIATION. 
‘HE South African Association for the Advance- 
ment of Science held its thirteenth annual 
session during the first week of July, at Pretoria, 
under the presidency of Mr. R. T. A. Innes, Union 
Astronomer. Notwithstanding the war, festivities and 
excursions took place as usual, and not the least in- 
teresting and instructive of the latter were visits to the 
Government School of Agriculture at Potchefstroom, 
to the Bacteriological Research Laboratory at Onder- 
stepoort—said to be the finest institution of its class in 
the world—and to the 2100 ft. level of the Crown 
Mines near Johannesburg, which has subterranean 
galleries extending over an aggregate of 1co miles. 
It so happened that, on the very day when the news 
of the surrender of German South-West Africa was 
received, Mrs. Botha had arranged to visit the asso- 
ciation in session at the Transvaal University College ; 
she was accorded a great ovation, after which the 
members sang the National Anthem. 
The papers read numbered nearly eighty, and out- 
lines of some of them, as well as of the four sectional 
presidential addresses, are given below. 
The presidential address given before Section A by 
Mr. F. E. Kanthack, director of irrigation of the 
Union, was a historico-scientific account of the de- 
velopment of the internal-combustion engine, the 
development of which is probably the greatest engineer- 
ing feat the world has ever seen. This factor in the 
war is entirely novel, and has had more far-reaching 
effects than anything else. It is scarcely possible to 
realise and appreciate the enormous amount of scien- 
tific work and inventive genius which has been ex- 
pended on the motor-car, and especially on the engine. 
New metallurgical processes had to be invented to pro- 
duce steels of great strength to survive the shocks and 
strains of hard-running, and the various machine tools 
and manufacturing processes connected with motor-car 
construction are no less wonderful than the finished 
article. What the steam engine was to the nineteenth 
century the internal-combustion engine is to the twen- 
tieth, and the effect of the latter on society is probably 
greater and more far-reaching than was the case with 
the steam engine. 
The president of Section B, Mr. H. Kynaston, direc- 
tor of the Union Geological Survey, died during the 
week preceding the association’s meeting, and his 
address was read by the sectional secretary after a vote 
of condolence had been adopted. Its theme was 
‘ Radio-activity in its Bearing on Geological Problems.”’ 
The address referred to the significance of the results 
regarding the concentration of radio-active com- 
pounds, although the data are as yet scarcely sufficient 
for definite conclusions. The view was expressed that 
either radio-active elements are absent from the more 
central portion of the earth, or present to an inappre- 
ciable extent, or else some agency such as pressure is 
able to restrain radio-activity in depth, or altogether 
prevent atomic disintegration. As the latter alterna- 
tive does not seem to conform to observation, it would 
appear that radio-active elements are confined to the 
crustal portion of the globe. The address then went 
on to discuss the bearing of meteorites on the idea 
of a radio-active crust, the conclusion being that the 
evidence certainly lends support to that theory. 
Section C also had to meet without its president, 
Mr. C. P. Lounsbury, chief of the division of ento- 
