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worthy and various. The Mount Wilson Observatory 
shows photographs of vortex rings in water and in 
air, and compares them with hydrogen flocculi about 
sun-spots, and spectra of spots showing the displace- 
ment, and the tripling and quadrupling of lines cue 
to the magnetic field. Photographs of various 
zodiacal lights, in which the effect of the exceedingly 
feeble luminosity is greatly increased, are from the 
University of Arizona. The various methods of dis- 
covering double stars employed at the Harvard Col- 
lege Observatory, and summaries of the results, are 
made interestingly clear by the contributions of Prof. 
Pickering. Dr. Nutting, of the Kodak Laboratory, 
sends results of lens testing, in which the figures of 
a luminous point yielded by lenses at various angles 
from the axis and different minute distances from the 
focus are remarkably well defined though magnified 
60 diameters. An excellent series of the effects cf 
spark discharges on photographic plates by Dr. 
Hoffert, results obtained with a ‘‘ micro-kinetograph” 
apparatus by Mr. Martin-Duncan, high-power photo- 
graphs of diatoms by Mr. E. A. Pinchin, and a selection 
of high-speed photographs by Dr. Abrahams, deserve 
special notice in the scientific and technical section. 
The natural history, colour, and other sections show 
no falling off in interest. 
Two waterspouts were seen off Dymchurch in 
Kent on August 16 shortly after 1 p.m., and they are 
described in the Times of August 19 by Rev. Henry 
Harries. The morning had been fine, and a thunder- 
storm was in progress at the time. The waterspouts 
were of the usual kind—a long narrow funnel con- 
nected a dark cloud with the surface of the sea, at 
a point where the surface was violently agitated. In 
one case, the funnel was seen to be in rapid rotation, 
while downward and especially upward movements 
were also discernible. The waterspout at sea and the 
tornado on land are manifestations of great instability 
of the atmosphere in a vertical direction, caused 
either by an abnormally warm surface layer of air or 
an abnormally cold layer at the cloud level. The 
former cause is common in summer; the latter occurs 
both in summer and winter, and is usually associated 
with a ‘‘line-squall’’ or V-shaped barometric de- 
pression. The waterspout shows the track along 
which surface air passes spirally upwards to restore 
equilibrium. The commotion of the sea is due to 
the exceedingly violent character of the phenomenon. 
The funnel itself is probably composed partly of 
moisture condensed out of the air by the sudden 
diminution of pressure which occurs, and partly of 
sea-water in the form of spray. Sometimes the middle 
portion of the visible funnel is absent, but there must 
be in that case a corresponding complete funnel of 
rotating air from the surface to the cloud. 
A uSEFUL article on the war and English chemical 
industry is contributed to the August Fortnightly 
Review by Mr. John B. C. Kershaw A comparative 
analysis is given of the British and German exports 
of manufactured chemicals, showing that whereas the 
bulk of the British exports consist of heavy chemicals 
and ‘‘crude products,’ the German exports to this 
country; which have a value twice that of the British 
NO. 2391, VOL. 95] 
NATURE 

[AucusT 26, 1915 
exports, consist mainly of fine chemicals, dyes, and 
pharmaceutical products. In the manufacture of the 
former a minimum of skilled labour and supervision 
is required, whilst in the German manufactures the 
opposite is the case. Mr. Kershaw again emphasises 
the fact that in Germany the directors and managers 
of chemical works are men whose business training 
has been superimposed on that obtained at a uni- 
versity, and who therefore have a thorough knowledge 
of the scientific side of the business, and realise the 
necessity for calling into their councils the best scien- 
tific and engineering knowledge available. One of 
the most important results of this is that they are not 
impatient of the time taken or success achieved by 
research work, and their knowledge of chemistry 
renders them less liable than inexperienced men to 
expect impossible results. A second factor of import- 
ance in the success of the Germans in the manufacture 
of fine chemicals is that resulting from the cleanli- 
ness, orderliness, and discipline of the German worker. 
This is attributed in no small part to the training 
gained during the period of military service. The 
article closes with a discussion of the prospects for the 
industry of fine chemicals and dyes in this country in 
the future, when the war has ended and the Germans 
again become active competitors. 
THE arboretum at Tortworth Court is well known 
to be one of the finest in the British Isles. One 
feature of particular interest lies in the fact that the 
collection is entirely the work of the present Earl of 
Ducie, who has been planting assiduously for sixty 
or more years, and many rare species are here repre- 
sented by the finest specimens of their kind in the 
kingdom. As the grounds rest on mountain lime- 
stone and Old Red Sandstone a useful choice of sites 
is afforded, and on the latter rhododendrons and 
allied plants thrive. An interesting account of the 
collection is given by Mr. W. J. Bean in Kew Bulletin 
No. 6, 1915, and particulars of the more notable speci- 
mens of oaks, chestnuts, maples, etc., are recorded, 
the latter being a remarkably fine collection. The 
golden chestnut, Castanopsis chrysophylla, from Cali- 
fornia, is one of the most famous trees, and was 
planted by Lord Ducie sixty years ago. The Ant- 
arctic ‘‘beech,’” Nothofagus obliqua, from southern 
South America, is also forming a handsome tree. 
The famous Tortworth sweet chestnut, with a trunk 
about 51 ft. in girth, is still alive, and is the tree 
under which King John is said to have held council; 
as early as Stephen’s reign Evelyn says it was known 
as the Great Chestnut of Tortworth. 
VALUABLE work is being undertaken in studying 
the characters of the sugar-canes cultivated at Sabour 
by Mr. E. J. Woodhouse, economic botanist to the 
Government of Bihar and Orissa, and Mr. S. K. 
Basu, assistant professor at the Agricultural College, 
and their results up to the present are published in 
Memoirs of the Department of Agriculture in India, 
vol. vii., No. 2. As in work of a similar character 
on other plants, the authors find that it is necessary 
to study varieties which have been derived from a 
single plant culture. Twenty-one different characters, 
relating to field appearance, the leaves, and the 
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