206 
OUR ASTRONOMICAL COLUMN. 
BriLtiant METEOR OF OcTOBER 7.—.A very 
meteor, which illuminated the heavens like a flash of 
lightning, was observed at various places in the west 
of England on October 7 at 10.35 p.m. It was seen 
by Mr. F. T. Naish at Bishopston, Bristol, and he 
recorded the position of the streak, which endured 
for nearly half a minute, as from 337°+8° to 327°—2°. 
As observed by Miss Eleonora Armitage at Swains- 
wick, near Bath, the meteor is described as coming 
rapidly from overhead and disappearing in Aquila. It 
left a luminous trail about 10° long, lasting for a few 
seconds. 
Mr. F. C. Carey, of H.M.S. Illustrious, Devonport, 
noticed a lightning-like flash, and on looking up- 
wards saw in due east, altitude 60°, a luminous train 
which was brighter in the upper portion and remained 
visible for several seconds. 
The meteor was also visible from Keynsham, near 
Bristol, and by several other observers at Bristol. 
From the data collected by Mr. Denning, he finds 
that the meteor had a probable radiant in Gemini, 
and that its height was from about seventy-four to 
fifty-two miles. The position of the flight was from 
over Wiltshire to the English Channel, about ten 
miles east of Paignton, Devonshire. Further observa- 
tions are needed of a more exact character to deter- 
mine its real path accurately. The meteor was a very 
swift one of the Leonid type, and it appeared on a 
very unsettled, showery evening, when, unfortunately, 
the sky was cloudy at many places. 
COMETARY OBSERVATIONS IN 1909 TO 1912.—The 
principal contents of No. 12 of the Mitteilungen der 
Hamburger Sterwarte relate to the observations made 
of comets which appeared in the interval included 
in the years 1909 to 1912. The observations there 
recorded are both visual and photographic, the former 
being made with an equatorial’ of 256 mm. aperture 
and 3:02 m. focal length, and the latter with a 
158 mm. Petzval objective of 760 mm. focal length, 
and a 5-in. Cooke triplet of 600 mm. focal length. 
Dr. K. Graff gives an account of the physical observa- 
tions made with the large equatorial, and accom- 
panies his remarks with an excellent series of draw- 
ings of the detailed structures in the heads of the 
various comets observed. Prof. A. Schwassmann 
limits his account to Brooks’s comet’ (1911c), and 
describes in detail the chief points which are notice- 
able on the fine series of photographs which accom- 
pany the text. This publication also includes the 
observations made for the determinations of the posi- 
tions of the comets and numerous minor planets, all 
made with the large equatorial by the observers, Dr. 
K. F. Bottlinger, Dr. K. Graff, and Herr H. Thiele. 
NORMAL SYSTEM OF WAVE-LENGIHS IN THE SPECTRUM 
OF THE IRON Arc.—In this column for October 2 refer- 
ence was made under the heading ‘‘The Wave- 
lengths of Certain Iron Lines”’ to the work of Dr. F. 
Goos. The current number of The Astrophysical 
Journal (vol. xxxviii., No. 2, p. 141) contains a further 
contribution by him towards ‘“‘the establishment of a 
normal system of wave-lengths in the arc spectrum 
of iron.’’ The main object of the communication is 
to show that it is not sufficient to prescribe a current 
of 5 to 10 amperes for the arc, as was adopted by 
the International Solar Union, but that it is abso- 
lutely necessary to define the manner of burning and 
the part of the arc used. Dr. Goos recommends the 
following procedure, based on many experiments :— 
For the normal spectrum of iron he proposes an 
arc 5 mm._long (separation of the rounded ends from 
each other) between iron rods 6 mm. in diameter and 
with a current .of 4 amperes. It should be used on a 
NO. 2294, VOL. 92] 
fine _ 
NATURE 
[OcTOBER 16, 1913 
220-volt circuit; the potential difference at the are | 
then falls to between 45 and 49 volts. It should be 
used with a pole changer, and the arc so projected — 
on the slit of the spectrograph with the condensing 
lens that only a portion of the are at the middle is 
used extending 1-5 mm. vertically at most. In order 
to show the importance of specifying exactly the are 
conditions to be ‘used, he directs attention to the — 
difference in the values of the three observers of the — 
normals of the second order. Thus he compares the — 
wave-lengths of the iron arc as published by Kayser 
and himself with the measurements of St. John and — 
Ware. He also includes measurements of the widths — 
of some selected iron lines. The main cause of all 
the differences is due to pressure changes, and the 
whole investigation shows that the iron arc is far from 
homogeneous. Dr. Goos finally questions whether 
the measurements of the normals of the third order 
form a really homogeneous system, and he proposes 
that an entirely new series of observations should be 
made with more uniform light-sources. 
MICROSCOPICAL EXAMINATION OF SKIN 
AND LEATHER. 
[IN the May number of the Bulletin de la Société — 
d’Encouragement pour l’Industrie Nationale, M. 
Georges Abt, of the Pasteur Institute, contributes an 
interesting and valuable paper on the microscopical 
examination of skin and leather, with special refer- 
ence to salt stains and their effect. 
The author first describes in detail the methods used 
for cutting and staining sections of skin. These are 
the general methods familiar to microscopists, but 
are varied slightly in order to differentiate the im- 
portant histological elements of the skin for the par- 
ticular purpose in view. The author endeavours to 
classify the different changes taking place in the skin 
during the various processes of manufacture into 
leather, and even goes so far as to suggest that the 
microscopical examination of the skin or hide in the 
various stages might be used to control the various 
processes. . 
In connection with his special investigation, the 
effect of salt stains, the author has prepared sections 
of the grain, flesh, and interior of the raw skin, the 
pelt, and of the finished leather, showing the char- 
acteristics of salt stains and their effect. 
The work is supplementary, and supports the hypo- 
thesis deduced by the same writer from a chemical 
investigation of these stains (‘‘Collegium,’’ 1912, 
pp. 388-408). M. Abt differentiates between two types 
of salt stains. Stains of the first class are distin- 
guished by the presence of calcium phosphate in 
places where grains of calcium sulphate have been 
deposited from the salt. In the section through 
these stains the nuclei of the connective tissue 
are very prominent. The author has proved 
them to contain iron and excess of tannin 
in the sections of stained leather. He assumes 
that these nuclei have been protected from the de- 
structive action of micro-organisms in the preliminary 
processes by an envelope of an organic iron salt and 
of iron and calcium phosphate, and he goes on to 
show that as the salt stain progresses the nuclei 
ultimately disappear, the connective tissues being dis- 
integrated, but not completely decomposed, as they 
would be by the action of bacteria, as claimed by 
Becker. 
The second kind of stain investigated only applied 
to horse hides and to leather made therefrom. These 
are characterised by the presence of strongly pig- 
mented epithelial tissues and the complete absence of 
calcium phosphate. The writer assum ss, therefore, 
