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FEBRUARY 12, 1914] 
Tue report of the (Egyptian) Zoological Service for 
1912 contains reproductions from photographs of some 
of the more interesting animals in the Giza Zoological 
Gardens. The Government, it appears, has been 
taking measures for the protection of certain kinds 
of birds, particularly the cattle-egret (Ardea bubulcus). 
That species has suffered so severely from the plume- 
hunters that in the spring of 1912 only a single breed- 
ing colony remained in the whole of Lower Egypt. 
Thanks, however, to protective measures, more than 
500 young birds were bred under natural surroundings 
under the care of a watchman of the Zoological Ser- 
vice. In Upper Egypt one large breeding colony 
remains, and, as the watchman reported the presence 
of a very large number of young birds in the country, 
there may be others. 
In Symons’s Meteorological Magazine for January 
Mr. R, C. Mossman concludes the seventh of his 
interesting articles on southern hemisphere seasonal 
correlations, with some remarks as to the practical 
value of this class of research. He considers it almost 
certain that interaction is world-wide, but that even 
to-day there are not sufficient weather data for many 
regions. As an essential feature of this study a 
bipolar campaign is suggested, and also that the 
equatorial belt should be specially investigated. The 
method of using the preceding weather in one part 
of the earth as a means of arriving at a knowledge 
of what will subsequently take place in another part 
has already had practical application in determining 
the probable intensity of the Indian monsoon. He 
thinks that the establishment of a world-bureau is 
the only way to meet the situation, owing to the 
enormous labour involved; this question has, however, 
been discussed at several of the international meet- 
ings, but all efforts to found such an institution have 
hitherto failed. 
Tue December number of Terrestrial Magnetism 
and Atmospheric Electricity contains the results of the 
determinations of magnetic declination made by the 
survey ship Carnegie on the voyage from St. Helena 
to Falmouth during the autumn of 1913. From these 
results it appears that the British chart of the Atlan- 
tic shows the westerly declination too small by about 
o-7° over that part of the course between latitudes 
5° south and 20° north, and about the same amount 
too great between 35° and 45° north. According to a 
note in the same number the Carnegie has now re- 
turned to New York, having completed her circum- 
navigation cruise of 70,000 miles commenced in June, 
IgI0, 
Tue introductory remarks on galvanometers and 
their properties with which the Cambridge Scientific 
Instrument Company prefaces its new catalogue of 
those instruments will prove of the greatest value to 
all who have to deal with electrical measurements. 
They cover such subjects as the period, the damping, 
the steadiness of the zero, the resistance, and the 
sensitiveness of the instruments, and furnish a sounder 
scientific basis for the choice of a galvanometer for 
any special purpose than can be found outside the 
scientific papers dealing with the subject. In order 
-NO, 2311, VOL. 92] 
NATURE 
669 
to compare different types of instruments a ‘‘ factor of 
merit '’ ts calculated from the behaviour of each. It 
is defined as one hundred times the deflection in 
millimetres. per -micro-ampere at a scale distance of 
a metre, divided by the square of the undamped 
periodic time in seconds and by the two-fifth power 
of the resistance of the instrument. The values are 
roughly one hundred for the Ayrton-Mather ordinary, 
zoo for the short-period instrument, 7ooo for the 
Paschen, 150 for the Broca, and 100,000 for the 
Einthoven string instrument. In the last case the 
comparison is somewhat doubtful, as the deflections 
are read through a microscope, and not in the standard 
way described in the definition. 
One of the subjects dealt with in a recent paper by 
Mr. B. Welbourn, entitled ‘‘ British Practice in the 
Construction of High Tension Overhead Transmission 
Lines,’’ and published in the Journal of the Institution 
of Electrical Engineers for January 15, was protection 
against atmospheric disturbances, He expressed the 
opinion that no necessity exists in this country for 
earth wire protection above the power lines, as experi- 
ence has shown that lightning troubles are very few 
and no more frequent than are mechanical faults on 
underground cables. Horn gap arresters, with or 
without choking coils, erected in the open air, 
especially in industrial districts, he condemned as 
wrong in principle, as well as being untrustworthy. 
The extensive use of electrolytic aluminium arresters 
is limited by the fact that they need charging every 
day from the line. Moscicki condensers are coming 
into favour slowly, possibly because of their high first 
cost. A novel method which has been found satis- 
factory has been developed by Messrs. Merz and 
McLellan, who have discarded arresters on all lines 
which are connected to the system through trans- 
formers. About 10 per cent. of the end turns on the 
line side of these are insulated with special materials 
to a thickness of 300 to 400 per cent. of the insulation 
on the remaining turns. Atmospheric disturbances on 
the line are reflected back by the end turns of the 
transformers, and the oscillations are damped out by 
the ohmic resistance of the line, 
THE Mathematical Association has issued a cata- 
logue of the current mathematical journals of all 
countries of the world, with lists of the libraries in 
Great Britain where they are taken in, and the dates 
at which the series commence and terminate when 
discontinued. This valuable little pamphlet is pub- 
lished by Messrs. G. Bell and Sons, Ltd., London, 
price 2s. 6d., and editorial communications for inser- 
tion in future issues are to be sent to Mr. W, NE 
Greenstreet, The Woodlands, Burghfield Common, 
near Mortimer, Berks. The present catalogue is 
issued on the understanding that it contains a first 
draft of the titles of current mathematical periodicals, 
Many periodicals of a general character containing 
mathematical articles are also included in its scope, 
though publications such as those of our Royal Society 
are excluded. The catalogue should be in every public 
library and in the library of every mathematician ; it 
contains 182 entries. 
