46 
NALORE 
[Marcu 11, 1915 

other all-important factors governing their production 
and application. 
Engineering for March 5 contains an illustrated 
description of Lord Chetwynd’s electrical steel-purifi- 
cation process, which has been in use for the past 
eighteen months at the Grimesthorpe Works, Sheffield, 
belonging to Messrs. Cammell, Laird and Co., Ltd. 
The steel is manufactured in the ordinary way in 
the Siemens-Martin furnace, and is then teemed into 
a special ladle. When teeming steel into a ladle in 
the ordinary way, a portion of the slag is drawn out 
with it, and becomes so intermingled with the steel 
in the ladle that it has no time to separate completely 
and to rise to the surface before the pouring into the 
ingot moulds takes place. Lord Chetwynd’s process 
is applied to the steel in the ladle. Two graphite 
electrodes are made to rest in the layer of slag cover- 
ing the molten steel in the ladle, and iron electrodes 
are fitted in the bottom of the ladle. As soon as the 
graphite electrodes are lowered into the layer of slag 
an electric current is made to flow through the steel, 
the effect of which is to raise the temperature of the 
metal, causing a rotating action throughout the molten 
mass, with the result that it is freed from the gases 
and slag particles which it contained in teeming from 
the furnace. The process lasts about thirty minutes, 
and the current expenditure is small. Test results 
show that the process has a marked refining action 
upon the metal in the ladle. 
OUR ASTRONOMICAL COLUMN. 
Mettisu’s Comer.—A note in the Times of March 
ro states that the orbit of this comet obtained by 
Andersen and Fischer, of Copenhagen, places peri- 
helion passage at about 1 p.m. on July 25 next, the 
distance being 110 million miles. The comet will 
remain visible to Knglish observers up to the middle 
of May, by which time it is likely to be faintly dis- 
cernible with the naked eye. It now rises about half 
an hour after midnight, the best time for observation 
being 5 a.m., when it is a little east of south. Its 
positions at 5 a.m. on the dates named are as 
follows :— 
R.A. Decl. 
S m. Se = i ‘ 
NENT “Ye ty Ba 2 0 ON 
TGGe scl Ae OME tn eOl 2 
20M o:-- FOS acon OL wt 
A Ben GP EG OD” ced Oh 2 ISK 
Tue British Ecripse Expepitions or 1914.—The 
January number (vol. Ixxv., No. 3) of the Monthly 
Notices of the Royal Astronomical Society contains 
the preliminary reports of the various British expedi- 
tions which were dispatched last year to observe the 
total eclipse of the sun on August 21. These reports 
have now been issued also in a separate pamphlet, and 
distributed by the secretary of the Joint Permanent 
Eclipse Committee. Brief accounts of the work of 
each of these expeditions have already been given in 
this journal, so attention need only be directed to the 
handy collective publication mentioned above. 
AsTRONOMY IN AMERICA.—With a_ strong editorial 
board the National Academy of Sciences of the United 
States of America has begun a publication of monthly 
proceedings. These proceedings will be official, and 
are intended to serve as a medium for prompt pub- 
lication of brief original papers. It is intended that 
the papers will be shorter and less detailed than those 
NO. 2367, VOL. 95] 
| of temperature, by 

published in journals devoted to special branches of 
science, and that they shall, if possible, include an 
introductory statement of the general aspects of the 
research, and of its relation to previous knowledge in 
the same field, so that its significance may be appre- 
ciated by those engaged in other branches of science. 
In the first number (January 15, vol. i., No. 1) astro- 
nomy is well represented bythe following communica- 
tions :—The radial velocities of nebula, by W. W. 
Campbell; Preliminary note on nebular proper 
motions, by H. D. Curtis; Discovery of the ninth 
satellite of Jupiter, by S. B. Nicholson; Spherical 
aberration in astronomical objectives due to changes 
F. Schlesinger; The relations 
between the proper motions and the radial velocities 
of the stars of the spectral types F, G, Kk, and M, by 
J. C. Kapteyn and W. S. Adams; and, finally, a 
critique of the hypothesis of anomalous dispersion in 
certain solar phenomena, by C. E. St. John. 
GRUNDSPECTRA OF ALKALI AND ALKALINE EAarti 
Merats.—A research interesting to spectroscopists is 
that communicated to the Astrophysical Journal for 
January (vol. xli., No. 1, p. 16), by Mr. Edgar H. 
Nelthorpe. The work was carried out in the astro- 
physical laboratory of the Imperial College of Science 
and Technology, and deals with the observations of 
the grun@spectra of allxali and allsaline earth metals. 
The term grundspectra refers to spectra obtained by 
Goldstein, who used a method by which line spectra 
of some elements were obtained which were totally 
different from their are spectra and could not be 
arranged in series of the ordinary type. As Gold- 
stein’s method appeared in some cases completely to 
isolate enhanced lines (spark) from the are lines 
occurring under the ordinary are or spark conditions, 
the author of the present paper has repeated and 
extended this research, embodying some of the spectra 
of elements which are represented in stellar spectra. 
The elements here dealt with are sodium, potassium, 
rubidium, calcium, strontium, and barium. Mr. 
Nelthorpe describes the apparatus he employed, and 
gives the results of each element separately, accom- 
panying them with a series of excellent photographic 
comparison spectra. The chief conclusion drawn is 
that the grundspectra obtained by Goldstein’s method 
consist essentially of lines which are specially de- 
veloped in the ordinary spark spectrum. In the case 
of potassium and rubidium the spectra consist entirely 
of enhanced lines, but with the calcium group the 
are spectrum is not entirely absent. 
ELECTRONS IN THE SUN’S ATMOSPHERE.—In a 
paper communicated to the Tokio Mathematico- 
physical Society in October, 1914, Prof. H. Nagaoka 
directs attention to the important part which may be 
played by calcium in the production of electrons in 
the sun’s atmosphere. In the flocculi so abundant in 
the photosphere it exists probably as calcium oxide, 
and the electronic emission of lime when incandescent 
is frequently utilised in laboratory work. At the 
pressure of one-tenth of an atmosphere which prevails 
in the calcium layer about a sun-spot, the electrical 
conductivity will not be too great to allow of con- 
siderable potential gradients which, according to their 
direction, will establish outward or inward electronic 
currents of considerable magnitudes. If, as seems 
most likely, the electric field is directed inwards, 
the electronic emission will be outwards and the 
regions of emission will be surrounded by electronic 
vortices with counter-cloclwise rotation. Within the 
vortices magnetic fields will be produced, and the 
whole region will possess the properties found to exist 
in ‘sun-spots. Comparisons of some of the conse- 
quences of this theory with observations are, it is 
hoped, to be carried out by the author and his pupils. 

