86 
ings, &c. A comparison of this collection of 
machinery with that in a modern steam locomotive is 
greatly in favour of the latter. Neither does the 
Diesel locomotive appear to show up any too well as 
a power plant; one horse-power is developed for about 
1go Ib. weight. A modern steam locomotive develops 
one horse-power for about 100 Ib. of engine weight, or 
for every 140 to 150 Ib. of combined engine and tender 
weight. Rapid perfecting of this type of engine is 
not to be expected, but it is to be hoped that the 
efforts instituted on the Continent will be persisted in. 
The greater the initial handicap, the more glorious 
the ultimate victory. 
ATTENTION may be directed to a slight error in the 
date assigned to Messrs. Cartailhac and Breuil’s mono- 
graph on ‘‘La Caverne d’Altamira’’; the frontispiece 
bears the date 1906, but this work was not published 
until 1908. 
OUR ASTRONOMICAL COLUMN. 
Tue Roratinc Exiipsoi RU CameLoparDaLis.— 
The elaborate investigations recently carried out by 
Prof. H. N. Russell upon the treatment of photo- 
metric observations of variable stars have been the 
means of bringing to light a new class of these bodies. 
By taking into account the hypothetical, but, of course, 
quite possible ellipticity of the components of a binary | 
system, a method was developed which may be applied 
equally well to the case of an isolated rotating ellip- 
soid—an early stage in the development of a binary 
system. At Princeton during the last two years the 
light changes of three stars—S Antliz, SZ Tauri, and 
RU Camelopardalis—have been explained in the most 
satisfactory way on the hypothesis that they are rota- 
ting ellipsoids. In Bulletin No. 21 of the Laws Ob+ 
servatory Mr. Harlow Shapley discusses 292 photo- 
metric measures of the third of these stars, and comes 
to the conclusion that “the light variations . . . can 
be satisfactorily accounted for on the hypothesis of a 
single, uniformly luminous, ellipsoidal body rotating 
in a period of 44-344 days.’’ With regard to the spec- 
trum of this star the author quotes a letter from Prof. 
E. C. Pickering to the effect that it is peculiar and 
apparently variable, and that Miss Cannon thinks it 
may belong to class N. 
The publication of the curves and results for S Antlize 
and SZ Tauri is promised for the near future. As 
both these stars have spectra of classes much less 
prone to variability of a physical character the realisa- 
tion of this promise will be awaited with great interest. 
THE DIMINUTION OF THE SOLAR RADIATION IN 1912.— 
Further evidence regarding the existence of a wide- 
spread atmospheric opacity during 1912 appears in a 
note by M. Ladislas Gorczynski in the Comptes rendus 
(vol. clvii., No. 1). The pyrheliometer record made at 
Varsovie shows that during the latter half of the year 
there was a marked falling off in the intensity of the 
solar radiation. The detailed measures, we are in- 
formed, show that the depression lasted from about 
the middle of June, 1912, to the middle of January, 
1913, and was most severe in September. Similar 
results were obtained at the Meteorological Observa- 
tory of Olczedaj6w, and it is pointed out that 
analogous records were obtained at Mount Weather. 
Comet 1913b (Metcatr).—A supplement to Astro- 
nomische Nachrichten, No. 4679, contains a continua- 
tion of the ephemeris of this comet which was given 
last week, after the first approximate elements com- 
NO. 2290, VOL. 92] 
NATURE 
[SEPTEMBER 18, 1913 
puted by Prof. Kobold. The comet is slowly increas- 
ing in brightness, according to the ephemeris, but on 
September 3 it was observed as of magnitude 9:5, and 
on September 4 as of magnitude jo-o. : 
12h. M.T. Berlin. 
R.A Dec. Mag. 
hm. s. y ' 
Sept. 18 ... 6 6 18 +67 23°5 — 
niyeters (0°. Ov4 rons 68 86 10°3 
20... 5 5443 «- 68 54°0 _ 
Ai... 5.47 58 5. “eageson == 
22 - 5 40 26 7O 24°3 — 
23 Elsevieiiey 71 88 103 
24 Bee Aas 705250) — 
Comet 1913c (NEUJMIN).—This comet when first 
observed (September 3) was thought to be a minor 
planet, but later observation has suggested its 
cometary nature. Herr M. Ebell has computed the 
elements from the observations of September 6, 7, and 
8, and these, with an ephemeris, have been communi- 
cated in a Kiel circular. They are as follows :— 
T=1913 July 22.5755 M. T. Berlin. 
w =320° 56°70" 
2 =347° 19°42’ -1913°0. 
z= 12> (22-978 
log 7 =0°11296 
Ephemeris for 12h. M.T. Berlin, © 
R.A. Dec. Mag. 
hm. s. 5 7 
Sept. 18 22 43 10 -+4 93 =— 
19 22 42 40 4 27°7 _— 
20 22 42 10 4 45'5 11'2 
According to Dr. Graff, at Bergedorf, the comet 
showed a short tail on September 6, but on September 
8, from observations made at Pulkova, the object was 
recorded as stellar. 
New Laporatory Spectroscopic REsuLts.—The 
physicat laboratory of the Imperial College of Science 
and Technology is responsible for four different 
spectroscopic researches recently communicated to the 
Proceedings of the Royal Society (Ser. A., vol. Ixxxix., 
pp. 125-149). Mr. L. C. Martin, a research student, 
writes on a band spectrum attributed to carbon mono- 
sulphide, and has found a new spectrum consisting 
of a number of bands degraded to the less refrangible 
side, the wave-lengths of which he gives in his paper. 
Prof. Fowler records new series of lines in the spark 
spectrum of magnesium incidentally tying up the well- 
known spark line at 44481 in one of the series. In 
conjunction with Mr. W. H. Reynolds, research 
student, Prof. Fowler has another paper on additional 
triplets and other series lines in the spectrum of mag- 
nesium. Eight additional triplets have been measured 
in the spectrum of magnesium are in vacuo, six be- 
longing to the diffuse and two to the sharp series. 
single lines have been photographed, and four strong 
solar lines of unknown origin have been identified with 
lines of the Rydberg series. Two known lines, 5711-31 
and 4730-21, have been coupled up in a series with 
435453, @ previously unrecorded line. Mr. W. E. 
Curtis, the demonstrator of astrophysics, has a paper 
on a new band spectrum associated with helium, but 
the question of its origin is still doubtful, as hydrogen 
was present in all the tubes examined. A list is given 
of the wave-lengths determined. A search in celestial 
spectra was made, owing to its association with 
helium, but the result was negative. 
THe PERTH OpsERVATORY SECTION OF THE ASTRO- 
GRAPHIC CHART.—Vols. ii. and iii. of the Perth Ob- 
servatory (Western Australia) section of the astro- 
graphic chart have just come to hand. These volumes 
are two out of the thirty-six volumes which will be 
| published. The region of the sky assigned to this 
Four additional members of the Rydberg series of — 
