568 
OUR ASTRONOMICAL COLUMN. 
THe GREENWICH SECTION OF THE ASTROGRAPHIC CatTa- 
LOGUE.—At the meeting of the Royal Astronomical Society 
held on March 11, the Astronomer Royal gave the chief 
particulars concerning the first part of the Greenwich section 
of the International Astrographic Catalogue, which is now 
quite ready for publication. The whole section comprises 
the region between declination +64° and +90°, whilst the 
part soon to be published deals with the region +64° to 
+72° inclusive, and covers 1077 square degrees, containing 
£0,000 stars. From the results already obtained it is com- 
puted that the complete Greenwich contribution to the 
catalogue will include about 179,000 stars. 
In his communication Mr. Christie stated that the 
number of stars per square degree increases with the de- 
clination until a maximum is reached at +76°; this effect 
is probably due to the Milky Way. A discussion of the 
relative magnitudes of the stars obtained on the catalogue 
plates has shown that stars down to at least the eleventh 
niagnitude appear on negatives which received six minutes’ 
exposure (the Observatory, April). 
Tue ComputaTiION OF ELEMENTS FOR AN ANNULAR 
Eciipse.—A paper by Herr Zwack, secretary of the 
Philippine Weather Bureau, issued as a supplement to the 
Bulletin for August, 1903, explains the method used in 
computing the elements for an annular eclipse of the sun. 
The method of successive approximations is illustrated by a 
detailed explanation of the procedure employed in computing 
the elements for the annular eclipse of March 17, 1904, as 
seen at San Domingo (Batanes Islands) and Manila (Luzon). 
Rapip CHANGES IN A SuN-spot.—In a communication to 
No. 343 of the Observatory, Mr. Denning gives particulars 
of some rapid changes which he saw take place in a sun- 
spot on January 22. The spot was one of four in the 
north-west quadrant, and it had a triple umbra. Whilst 
Mr. Denning was observing, one of these umbrz became 
greatly modified, and two new small spots appeared. Mr. 
Denning suggests that much valuable information regard- 
ing the behaviour, the formation, and the cyclonic con- 
ditions of spots might yet be obtained by more persistent 
observations. Solar observations generally terminate when 
the positions and forms of the spots have been recorded, 
and from these records valuable knowledge as to the period 
and loci of sun-spots has been deduced, but {or about the 
last forty years very little consistent work has been done in 
persistently noting the minute yet constant changes which 
take place in the disturbed regions about spots. 
Mr. Denning further suggests that daily observations ex- 
tending over several hours would probably produce results 
which would completely justify the outlay of the time 
necessary for making themni. 
PHo1oGRapiic OBSERVATIONS OF BORRELLY’s CoMET 
(1903 c).—A paper by Mr. Sebastian Albrecht in No. 2 
vol. xix., of the Astrophysical Journal describes thirty-one 
negatives of the comet 1903 c, taken at the Lick Observ- 
atcry, between June 22 and August 18 inclusive, with the 
Crocker telescope and the Pierson camera respectively. 
The negatives show two tails, one about 10° in length 
and generally straight, the other about 1°-5 in length and 
much curved. In addition to these, occasional streamers 
developed and were generally fairly persistent, narrow and 
straight, sometimes emanating from the main tail, some- 
times from the coma. The modifications in the main tail 
which have been previously noted by the observers at the 
Nanterre and Yerkes Observatories are very prominently 
shown on the negatives secured at Lick on July 23, 24 and 
26, three beautiful reproductions of which accompany Mr. 
Albrecht’s communication. The negative of July 23 shows 
an entirely new tail, having a length of about 4° and an 
angular width of about 4°-6, issuing from the head and pre- 
ceding the radius vector by about 6°. This feature is not 
shown on the negative secured on July 24. 
The paper also contains a discussion of the various 
changes, together with several tables giving the dimensions 
and positions of the tails and streamers which are shown 
on the negatives. 
NO. 1798, VOL. 69] 
NATURE 
[APRIL 14, 1904 
THE EVOLUTION OF EMPIRE. 
N° matter what may be the subject of investigation, the 
process of evolution always appears as a progressive 
movement from the simple to the complex, from homo- 
geneity to heterogeneity. It is so in zoology when the 
simple self-contained cell by segmentation sets out on the 
upward path of organisation; it is so in sociology when the 
primitive homogeneous community through division of 
labour takes the first step in civilisation; it is so in art; 
it is so in letters; it is so in all the multifarious domains 
of human experience, and the evolution of empire forms no 
exception to the rule. In every case the method is the 
same. The course pursued is a zig-zag or spiral, which 
tends now towards difference and again towards agree- 
ment; there is a constant ringing of the changes between 
variation and integration, and the goal is ultimately reached 
under the simultaneous or alternate influence of the forces 
of separation and union. 
In the cooperation of these apparently antagonistic 
factors towards a common end lies the paradox of all ages- 
It is the riddle of the sphinx which each succeeding gener- 
ation must solve or succumb. Ancient philosophy made 
many good guesses at the truth. Herakleitos, 500 B.C., 
wrote, ‘‘ Opposition unites; from what draws apart results 
the most beautiful harmony; all things take place by 
strife.’? Empedokles a few years later spoke of creation 
as the product of love and strife, ‘‘ From these come all 
things that are or have been or shall be.’’ Still later Plato, 
referring to the teaching of Empedokles, wrote, ‘‘ Being 
is many and one and is controlled by hate and love; borne 
apart it is always borne together.’’ The Persians per- 
sonified the antithesis under the dualism of Ormuzd and 
Ahriman, the powers of light and darkness. So universal 
is this concerted antagonism that it seems to be inherent 
in the very essence ‘of things, and is doubtless a manifest- 
ation of the polarity which pervades creation. Even in 
music, the most fugitive and intangible of arts, the process 
of evolution through difference and agreement is clearly 
marked. The simplest music is in unison—to this succeeds 
a differentiation into various parts, and these are ultimately 
blended in harmony. So that the sequence, here as else- 
where, is from unity, through difference, up to union, the 
reintegration being more complex and in a far higher 
plane of performance than the uniformity from which it 
was evolved. 
It was left for Darwin to focus the vague surmises of 
his predecessors and to demonstrate the systematic oper- 
ation of variation and integration in the production of new 
forms. Science since his day has been occupied in applying 
his theory to fresh fields of inquiry, and in no department 
has a richer harvest of results rewarded the investigator 
than in tracing the application of the laws of evolution in 
the development of communities. 
Comte was of opinion that the most fruitful results would 
follow the process of sociological suggestion followed by 
zoological verification, and striking confirmation of the 
efficacy of this method is found in the fact that Darwin 
got the first hint of his discoveries from contemplating the 
dilemma of Malthus with regard to population. This 
sequence is most rational, for selection has arrived at a far 
greater degree of finality and excellence in living forms 
than in social organisms. In each case nature proceeds 
by continual invention and experiment and ruthless dis- 
carding of failures, but in zoology the problems are simpler, 
because the factors are more determinate than in sociology. 
The rigorous dynamics of blood pressure and the limitation 
of speed of nerve currents are fixed conditions which pre- 
scribe the economic size of the individual. These conditions 
have existed since the beginning of the world—the necessity 
of rapid reaction to stimulus and of vascular efficiency 
has caused the elimination of the unwieldy antediluviam 
monsters in favour of the marvellously agile and tensely 
arterialised modern carnivora. 
In sociological problems the hand of nature is still that 
of the apprentice. New conditions as to communication 
and transport have rendered previous conclusions nugatory. 
The difference in speed of communication to-day as com- 
pared with 300 years ago is illustrated by the fact that the 
news of Queen Elizabeth’s death did not reach some parts 
