June 3, 1915] 
NATURE 
381 

In the Proceedings of the National Academy of 
Sciences, Washington (vol. i., p. 256), Dr. C. D. 
Walcott announces the discovery of bacteria in one 
of the petrified algze from pre-Cambrian rocks in 
Montana, to which reference was made in NATURE 
last weeks (p. 354). They appear in the algal tissue as 
irregular chains of darkly stained cells from 0-95 to 1-3 
microns in diameter, and are very suggestive of 
Micrococcus. It is not always possible to distinguish 
with certainty such fossils from purely mineral struc- 
tures, but satisfactory traces of bacteria have already 
been detected in the fossilised remains both of animal 
and plant tissues in European Palaeozoic rocks, and 
they are to be expected among the earliest organisms. 
TuroucH Mr. Bassett Digby, the geological depart- 
ment of the British Museum (Natural History) has 
lately obtained a well-preserved front horn of the 
woolly rhinoceros from the frozen earth of northern 
Siberia. The specimen measures nearly a metre in 
length, and, though partly cut as usual by the natives 
who found it, shows the backward curvature of its 
slender apex and the lateral compression of its 
characteristic sharp posterior border. The new horn 
has been mounted, with a hinder horn already in the 
museum, above one of the exhibited skulls of woolly 
rhinoceros from Siberia. It is thus possible to realise 
the unusually large proportions of the horns in this 
extinct species. 
THE question of the pollution of the air of our manu- 
facturing towns has been a serious one for some time, 
and the report of the Air Pollution Advisory Board of 
the city of Manchester will prove a valuable document 
to those seeking to mitigate a serious evil. It appears 
that the domestic grate is the principal offender and 
that the modern factory with mechanical stokers is 
comparatively, if not absolutely, innocent. In many 
cases, however, the impurities are not due to in- 
different stoking, and for these the electrostatic method 
of precipitation which has proved so successful in 
America) may be recommended. An _ interesting 
account of the method and the results of its application 
will be found in the Electrical Review for May 14. 
Briefly, the polluted air passes between electrodes 
maintained at a difference of potential of 100,000 volts, 
and the particles of carbon, arsenic, potash, or chlorine 
are carried by the! discharge to one of the electrodes. 
About five kilowatts are necessary to deal with about 
30,000 cu. ft. of air per minute, so that the cost is 
slight. In many of the cases cited the value of the 
material recovered in a year exceeded the cost of 
installation and working of the apparatus. 
Tue Times Engineering Supplement for May 28 
touches on a point in works organisation to which 
too little attention has been given in this country, 
especially in the case of small- and medium-sized 
factories. Before the war, our industries suffered 
severely from German competition; this has been 
attributed in varying degrees to free trade, lack of 
technical education, and so forth. As the output of 
our factories must now be increased, our contem- 
porary asks: Given perfect workmen and_ entire 
absence of alcohol, is the management of such a high 
order that the output is a maximum? Are the pro- 
NO. 2379, VOL. 95| 

prietors, or directors, so wholehearted in their patriot- 
ism that they lose no time? Are they so skilled in 
‘their respective spheres that they are able to guide 
their staff and workmen? In large firms the organisa- 
tion is generally of a high order of efficiency, but it 
must be confessed that a large number of small firms 
work from hand-to-mouth in such a manner that out- 
put and delivery of orders to a stated time are quite 
problematic matters. Many of these smaller con- 
cerns are in the hands of a family, or financial men, 
who know nothing of the work being carried on, and 
whose sole object is to derive as large an income as 
possible with the minimum of effort. Such firms 
which are not producing a good average should be 
visited by skilled managers, and the real cause located. 
If lack of capital is the cause, the Government should 
assist; if incompetent management, the offenders 
should be removed; and if the cause is lack of plant 
which cannot be immediately rectified, the factory 
should be closed and the men drafted to a _ well- 
organised concern. 
Tue director of the Geological Survey of the Union 
of South Africa asks us to announce that no annual 
report of the Survey will be issued for the year 1914. 
The announcement is made to spare the necessity of 
inquiries from the many scientific institutions, etc., 
which are on the complimentary list of the Survey. 
Erratum.—In equation 2 on p. 359 of Nature of 
May 27, the symbol T should appear as a factor in 
the denominator of the fraction, and there should be a 
minus sign before 7 in the numerator. Both omissions 
were overlooked by the author in two proofs corrected 
by him. 

OUR ASTRONOMICAL COLUMN. 
OBSERVATIONS OF NEBULA AT THE HELWAN OBSERVA- 
tory.—Mr. H. Knox Shaw describes in Bulletin 
No. 15 of the Helwan Observatory the observations 
made with the Reynolds reflector up to the end of Sep- 
tember of last year, this paper being a continuation 
of that published in Bulletin No. 9. This work is 
described as being somewhat of a reconnaissance to 
see which nebule would repay photographing with 
long exposures when the new Ritchey 30-in. mirror 
is mounted. The paper gives a list of the nebulz 
observed, and also one of thirty-one new nebulz con- 
firmations of which have been made by second photo- 
graphs in each case. Referring to N.G.C. 6729, the 
nebulz attached to the variable star R. Corone, 
Aust., the author states that this nebula is certainly 
variable, and the question as to how its variability 
is connected with that of the star is being studied, 
and is promised as a separate paper. 
Stars WITH PROPER Morion EXCEEDING 0:50" 
Annuatty.—Mr. Adriaan van Maanen contributes to 
the April number of the Astrophysical Journal (vol. 
xli., No. 3) a very useful list of stars with proper 
motion exceeding 0-50’ annually. This list is based on 
Porter’s and Kobold’s lists, which indicated proper 
motions greater than 0-50’ annually, on Bos- 
sert’s catalogue of proper motions of 2641 
stars, and on numerous other subsequently pub- 
lished notes on stars of large proper motion. 
The present list is made as far as_ possible 
homogeneous throughout, and deals with 533 stars. A 
column is given showing the spectra of the stars as 
determined by Mr. W. S. Adams or Miss Cannon. 
The positions in right ascension and declination are 
