136 
OUR ASTRONOMICAL COLUMN. 
FirEBALL OF OcToBER 3.—A large number of addi- 
tional observations have come to hand, and Mr. Den- 
ning writes us that the brilliant object was well 
observed as far north as Huddersfield and as far 
east as Hertford. Even at Huddersfield, where the 
observer was about 210 miles distant from the object, 
it exhibited a Venus-like lustre, and was followed 
until it disappeared in the mist very near the S.S.W. 
horizon. The new observations confirm, in general, 
the deductions already stated as regards the position 
and height of the fireball, but the exact place of 
the radiant point remains a little doubtful. With 
reference to the elevation at disappearance, this may 
have been less than thirty miles, for there are several 
observations indicating it at about twenty-four miles. 
The cloudy or misty condition of the sky at many 
places, however, hindered efforts at exact observation. 
Everywhere the spectators speak of the astonishing 
brilliancy of the object and admit that its’ startling 
aspect at first aroused fears of a calamitous sequel. 
Erratum.—By a clerical error Launceston was men- 
tioned instead of Seaton, East Devon, in Nature, 
October 12, p. 116. 
Anomatous DisPERSION IN THE SUN.—The search for 
evidence of anomalous dispersion in the sun continues 
to attract considerable attention. Dr. Albrecht recently 
concluded that Rowland’s measurements gave distinct 
indications of a mutual repulsion in close pairs of lines, 
such as is required by the anomalous dispersion theory. 
Mr. Evershed and Dr. Royds, however, have ques- 
tioned the validity of this result, since it is not sup- 
ported by data obtained at Kodaikanal by more direct 
methods (the Observatory, October, 1916). In agree- 
ment with Dr, St. John, Mr. Evershed finds that 
Rowland’s separations were almost invariably over- 
estimated ; for eighteen pairs having a mean separation 
of o-1920 according to Rowland, the Kodaikanal mean 
value was o0-1836. The tendency of Rowland was 
therefore to displace the violet components to the 
violet, and the red components to the red, thus simulat- 
ing the effects of anomalous dispersion. Mr. Ever- 
shed considers that his results are decidedly against 
the view that anomalous dispersion is an effective agent 
in displacing solar lines. 
Dr. St. John has also made an exhaustive examina- 
tion of the cases included in Albrecht’s list, and is 
strongly of opinion that the deviations are merely due ° 
to systematic errors in Rowland’s measures of close 
lines (Proc. Nat. Acad. Sci., vol. ii., p. 458). He finds 
that the separations of pairs in the solar spectrum are 
identical with those obtained from ‘terrestrial sources. 
“Within the limits of error, evidence of mutual influ- 
ence is absent from the solar spectrum, and in so far 
as mutual influence is a necessary corollary of 
anomalous dispersion in the sun, evidence for it also 
is absent.” 
Experimental work bearing upon this question has 
been carried out at the Pasadena laboratory by Dr. 
A. S. King (Proc. Nat. Acad. Sci., vol. ii., p. 461). 
Anomalous dispersion effects in metallic vapours were 
obtained by the use of the electric furnace, in which 
a strong density gradient was produced by water- 
cooling the upper part of the tube. Tests for the 
mutual influence of lines were made on the mixed 
vapours of titanium, calcium, and chromium, in which 
certain lines of the two former elements fall well 
* within the curved spectra given by the anomalous dis- 
persion of chromium lines. When compared with the 
corresponding emission snectra of the mixture, and of 
the elements separately, the measures gave no evidence 
whatever of a mutual repulsion between close lines 
when anomalous dispersion is active. 
NO. 2451, VOL. 98] 
NATURE 
[OcTOBER 19, 1916 
Tue VartABLE Star SZ CyGni.—Extensive observa-_ 
tions of SZ Cygni, covering the period from Novem- 
ber, 1912, to August, 1916, have been made by F. C. 
Leonard (Mon. Reg. Soc. Prac. Astr., vol. viii., No. 5). 
The star is of the 8 Cephei class, having a mean 
magnitude of 8-96 at maximum and 9-74 at minimum. 
The mean period is 15-10 days, with an interval of 
66 days from minimum to maximum. Both range 
and period appear to be subject to slight variations. — 
The star is stated to be of a reddish tinge, and to 
deepen in colour as the brightness diminishes. 
FISHERIES INVESTIGATIONS AND 
DEVELOPMENT. 
5) aaa importance of utilising more fully the fisheries 
around Our coasts was emphasised at the recent 
Newcastle meeting of the Britisn Association, one day 
being devoted to papers and discussions on this and 
kindred subjects. 
Prof. Herdman urged that with the view of making 
a rapid recovery from the elects of war, food-produc- 
ing industries should be encouraged, and, among 
otners, the inshore fisheries should be exploited. Shell- 
fish cultivation, shrimping and prawning, whitebait 
and sprat fishing, and herring fishing and curing, if 
extended and exploited judiciously, would add to em- 
ployment, increase the national food supply, and might 
lead to the establishment of permanent industries ol 
a profitable nature.. He illustrated by several instances 
how the transplantation.of stunted mussels from an 
overcrowded area to suitable neighbouring areas re- 
sulted in the rapid production of mussels of good 
quality which were sold for eight to ten times the 
sum expended on their transplantation. As examples 
of local fisheries started recently, Prof. Herdman men- 
tioned the winter sprat fishery in Morecambe Bay 
and the summer herring fishery in the Irish Sea. 
Prof. Meek gave an account of the inshore fisheries 
of Northumberland, and pointed out what had been 
done to preserve them by legislation and to encourage 
them by such an attempt as that now being made to 
establish a mussel-bed large enough to supply the 
wants of the district. The importance to the nation 
of the fishermen of the smaller fishing stations has 
been emphasised during the present war. With the 
problem of the preservation and extension of the 
coastal fisheries is involved the economic consideration 
of better buying and selling, and also the social ques- 
tion of making life in the fishing village more attrac- 
tive. 
In his paper on the further development of the — 
shell-fisheries Dr. James Johnstone dealt especially 
with the coasts of Lancashire, Cheshire, and North 
Wales, where such fisheries are of considerable actual 
value and of very great potential value. Here mussels 
and cockles exist in incredible abundance, though in 
certain areas a considerable proportion are always 
smaller than the specified legal size. Mussels are ~ 
found to prefer shallow estuarine water of low salinity 
containing the drainage from cultivated land or from 
human communities. Dr. Johnstone dealt with the 
rationale of successful transplantation, and calculated 
that the yield in assimilable food substance of high 
nutritive value of a cultivated mussel-bed was probably 
greater than that of a similar area of land bearing a 
food crop. He pointed out that although mussels feed 
on contaminated material they can be cleansed, and 
regarded as pure, by placing them in an area where 
water coming in from the sea washes over them 
during the last hour of flood-tide for two to four days. 
Although it is practicable to develop the yield of the 
shell-fisheries to an enormous extent, it is difficult to 
see how this can be brought about without some 
