tN 
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No 

Photograph of a Bright Meteor. 
ONSIDERING the great frequency of the appear- 
ance of bright meteors which flash across the 
night sky, it is astonishing how few photographs of 
them have been obtained. The actual photographing 
of a meteor is really quite a simple matter, but the 
whole success of the operation depends on whether 
the camera is pointed to 
the position in the sky 
where a meteor happens 
to pass. 
While any camera will 
serve the purpose, a suit- 
able instrument is one 
having a large aperture 
and short focal length. 
In a communication to 
the Royal Astronomi- 
cal Society (Monthly 
Notices, vol. 83, p. 92) 
Dr. W. J. S. Loekyer 
describes a very in- 
teresting photograph 
which he has secured, 
and also the instrument 
used. The lens is an 
old portrait doublet 
having an aperture of 
five and a quarter 
inches and a focal length 
of twenty-eight inches ; 
quite a suitable lens. 
This lens is mounted 
in a home-made box 
camera which carries a 
plate 84x64 in. The 
field of the lens covers 
about 16 degrees. 
For the purpose of 
photographing meteor 
trails, the camera is 
fixed firmly on a stand 
and pointed directly at 
the pole star. This 
direction is chosen be- 
cause the stars make 
their trails completely 
on the photographic 
plate, these trails being 
portions of small circles. 
By comparing such 
trails with a star atlas 
all the stars can be 
easily identified and 
the position of the 
meteor trail accurately 
deduced. It is Dr. 
Lockyer’s usual prac- 
tice, when working at 
night with the 9-inch prismatic camera of the Norman 
Lockyer Observatory, always to expose as long as 
possible one plate in this meteor camera, which is 
erected just outside the dome. 
During the night of November 16 last, the plate 
(Marion’s “‘ Record,’’ H.D. 500) was exposed from 
8b 58m to 112 12" G.M.T. In the course of develop- 
ment the first images to appear were the trail of the 
pole star and a long streak across the plate which 
was the trail of a bright meteor. A reproduction 
of a portion of this plate (reduced by one-quarter) 
is shown in Fig. 1. The photograph shows practically 
the complete length of the meteor trail. 
Considering the slowness of the movement of the 
NO. 2782, VOL. 111] 

Fic. 1.—Photograph of a Taurid 
fire-ball. 
NATURE 


image of the pole star (the short brightest trail near 
the pole) due to the earth’s rotation, and the relatively 
great speed of the meteor—probably in any portion 
of its trail only a very small fraction of a second— 
the brilliancy of the latter must have been very 
great, judging by the great density of the trail. 
The most striking feature of the meteor’s trail is 
the great differences in intensity along its path. 
In some portions it is so bright that it has produced 
halation on the photographic plate (unbacked) as 
strong, if not stronger, than the pole star itself. 
These intensity differences are due most probably 
to the unequal volatilisation of the material forming 
the meteor. 
It is interesting to note that the meteor trail, 
when traced on a celestial globe, passes close to a 
star named « Tauri, the radiant point, for that date, 
of slow-moving bright meteors, as determined by 
Mr. W. F. Denning. Evidently the meteor here 
photographed was a Taurid fire-ball and the brilliancy 
of its image was due to its comparatively slow motion. 


An Australasian Biological Collecting 
Expedition. 
THE native animals and plants of Australia are of 
exceptional interest, and many of them are 
likely to disappear, or at least to become rare, as the 
result of the extension of the settled areas of the 
country—a process which has already been in 
operation for many years. The Trustees of the 
British Museum, recognising the importance of 
securing an adequate representation of this remark- 
able fauna and flora while there is yet time, have 
made arrangements for a collecting expedition, which 
started from London a few days ago. Mr. G. H. 
Wilkins, to whom the leadership has been entrusted, 
has special qualifications for carrying out his task 
with success. He is Australian by birth, and he has 
a good knowledge of the country, where he has many 
friends from whom he may expect to receive valuable 
assistance. He has travelled extensively in various 
parts of the world, and he has already acted as 
naturalist to several important expeditions. He 
spent four years, 1913-1917, on the coast of Alaska 
and in the Beaufort Sea, as a member of the Stefansson 
Canadian Arctic Expedition. In 1920 he visited 
Graham Land with the Cope Expedition, and in 
1921-22 he was with the Shackleton-Rowett Ex- 
pedition, in the Quest, visiting South Georgia and the 
Antarctic Quadrant from Enderby Land to Coats 
Land. On the return journey valuable collections 
were made at Gough Island. 
Mr. Wilkins expects to be able to obtain assistance, 
partly voluntary, in Australia, and thus to be provided 
with a scientific staff among whom the various 
branches of the work will be distributed. A special 
effort will be made to obtain good series of mammals, 
birds, insects, and other members of the land fauna, 
and to spare some time for the collection of plants. 
He will collect first in Queensland, at one or two 
selected stations, going south when the rainy season 
commences, revisiting Queensland in 1924, and 
reaching the Cape York Peninsula in one or both 
years. 
: A preliminary survey, on a smaller scale, by a 
collector employed by the Godman Exploration Fund 
Trustees, has shown that the representation of 
Australian mammals in the national collection is 
by no means so complete as it should be; and there 
is good reason to believe that the projected expedition 
will add considerably to existing knowledge. This 
preliminary work has been rendered possible by a 
generous gift made by Dame Alice Godman and her 
[ FEBRUARY 24, 1923 - 

ee 
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