’ DECEMBER II, 1913] 
NATURE 
435 
of which marks it as one of exceptional interest. He 
describes it as a new variable star or nova, and its 
positions for two epochs were (1855), R.A. 22h. 56-3m., 
dec. +58° 52'; (1900), 22h. 58-1+59° 6-3'. The long 
period of brightness of the star and rapid decline 
suggest, as he says, that ‘‘we may be dealing with 
the later stages in the history of a nova.” Two charts 
taken on September 3, 1911, and August 25, 1913, 
exhibit marked changes in its magnitude. The same 
writer directs attention to some new nebulz in the 
region of I Cassiopeia. Dr. R. Furuhjelm, of the 
Helsingfors Observatory, describes two new variables, 
both of which have amplitudes of at least three mag- 
nitudes. He proposes to continue to observe these 
objects to secure correct determinations of their 
. periods. 
Warts’s INDEX oF SpEcrRa.—Yet another series of 
appendices to this most valuable compilation of wave- 
length data has been commenced by the publication of 
Appendix V. This part begins with the spectrum of 
the electric spark in air and extends to that of chlorine. 
The additions include measures of the spectra of the 
elements Aldebaranium, Cassiopeium, and Beryllium 
(band spectrum). Among spectra of compounds Olm- 
sted’s data for calcium hydride and Fowler’s carbon 
oxide spectra find a place. Perhaps it is not too late 
to make the suggestion that the policy of giving, in 
the briefest possible manner, an indication of the con- 
tents of the papers referred to be extended to include 
all references in forthcoming appendices. 
SECULAR DESICCATION OF THE EARTH. 
oy Monday, December 8, Prof. J. W. Gregory 
read a paper before the Royal Geographical 
Society, entitled “‘Is the Earth Drying Up?” The 
question is naturally one to which a definite affirma- 
tive or negative answer cannot be given owing to the 
relatively short period during which exact scientific 
measurements of precipitation have been made. The 
evidence is principally archeological, botanical, and 
geological, supplemented for some countries by historic 
records of population. Prof. Gregory put before the 
society the views of different investigators, and sub- 
jected them to a critical examination, confining him- 
self to changes in historical times, and making no 
pretence at dealing with the great changes of climate 
of geological epochs, other than to indicate the glaciers 
of north-west Europe as the probable cause of the 
moister Mediterranean climate of prehistoric times. 
There are, roughly speaking, three forms of the 
desiccation theory. Prince Kropotkin maintains that 
there is a world-wide tendency towards drought. 
Prof. Ellsworth Huntington believes that the most 
important changes are pulsatory, the climate being 
now drier, now moister, but in the long run becoming 
generally drier. Mr. R. Thirlmere holds that the 
climate varies in great cycles, each of which may 
extend over 2000 years or more, and that we are at 
present in a cooling world. Prof. Gregory examined 
the evidence from different countries in its bearing on 
these theories, and showed the results of his examina- 
tion on a map, from which it appears that there has 
probably been desiccation in historic times in Central 
Asia, Arabia, Mexico, and South America; increased 
precipitation in the United States of America, Green- 
land, Sweden, Roumania, and Nigeria, and no appre- 
ciable change in Palestine, northern Africa, China, 
Australia, and by the Caspian Sea. He deduces that. 
though there may be local variations, there is no 
progressive world-wide change to support the theory 
of a universal drought. A priori it might be affirmed 
that no appreciable universal change could occur with- 
out a corresponding considerable change in the dis- 
NO. 2302, VOL. 92] 
tribution of land and water, or in the intensity of 
solar radiation. The changes in the former have been 
small in historic times, and though no direct evidence 
of solar intensity is available, the records of tempera- 
ture and of plant life indicate that its fluctuations 
are probably confined to the short period variations 
found by the observers of the Smithsonian Astro- 
physica! Observatory. 
The strongest support for the desiccation theory is 
derived from Central Asia, where the evidence, though 
not conclusive, largely owing to the alternative ex- 
planation of blown sand, is sufficiently convincing to 
have won over the majority of the travellers who have 
visited that region. E. G 
ASTRONOMY IN SOUTH AFRICA. 
VERY interesting address was given by 
Dr. A. W. Roberts, as president of the South 
African Association for the Advancement of 
Science, at Lourenco Marques on July 7. Dr. 
Roberts dwelt for the main part on the progress made 
in astronomy by South African workers during the 
past century, but he claims pardon for omissions when 
such a large scope of work has to be considered. He 
sums up the work of astronomical science in late 
years as circling round three great problems, namely 
the distance of the stars, the movements of the stars, 
and the structure and evolution of the stars. These 
three lines, he points out, all converge in one great 
question, namely the constitution, history, and cosmo- 
graphy of the universe as a whole. In reading his 
address, which is published in The South African 
Journal of Science (vol. x., No. 2, October) one is 
struck by the great part that has been played by 
astronomers in South Africa. To use the president’s 
own words :—‘‘It was at the Cape that a sounding 
line was first thrown across the stellar space. It was 
at the Cape that the idea of stellar photography was 
born, grew up, and reached maturity. It was at the 
Cape, or perhaps by the results obtained at the Cape, 
that the first vision was got of those wonderful 
streams of stars that sweep majestically through our 
universe. It was at the Cape that the classical dis- 
tance of the sun was reached... that the first 
accurate parallax of the moon, and, later on, its 
weight, was determined ... that the most refined 
measures of stellar distance have been secured.’ Dr. 
Roberts tells the story of how—twenty years ago—he 
had in purpose the determination of the position of 
the solar apex from the proper motions in Stone’s 
catalogue. ‘‘I went,’ he said, ‘over my postulates 
with Gill, and was vehemently assured I was basing 
my equations on wrong premises. ‘How do you 
know that the stars move haphazard?’ he demanded. 
I did not know! ‘They may be moving in streams; 
the whole universe may be a big whirlpool! ’" The 
record of the past work of South Africa in astronomy 
) is great, and a high standard has been set for the 
| present and future astronomers there. 
THE ORIGIN OF ARGENTINE HORSES. 
1 ie the Anales of the Buenos Aires Museum for IgI2 
(vol. xii.) Sefior Cardoso adduced evidence to show 
that the story of the origin of Argentine horses from 
Spanish horses imported by Don Pedro de Mendoza 
in 1535 Or 1536 is a myth, and that the former are 
really descended from the Pleistocene Equus rectidens 
and E. curvidens, and existed in the interior of the 
country at the time of the Spanish conquest. This 
opinion is disputed in the Revue générale des Sciences 
of October 15 by Dr. Trouessart, who points out that 
the statement of wild horses having been seen by 
Sebastian Cabot in 1531 is based on the figure of a 
