AO 
Tue following books relating to science are 
announced, in addition to those referred to in our 
issue of March 5 :—In Anthropology—The Ban of the 
Bori: an Account of Demons and Demon-Dancing in 
West and North Africa, Major A. J. N. Tremearne, 
illustrated (Heath, Cranton, and Ouseley); in Biology 
—-The Wonder of Life, Prof. J. A. Thomson, illus- 
trated (A. Melrose, Ltd.); In Nature’s Ways, M. 
Woodward, illustrated (C. A. Pearson, Ltd.); 
British Flowering Plants, illustrated by Mrs. 
H. Perrin, with descriptive notes and an_ in- 
troduction by Prof. Boulger, 4 vols. (B. Quaritch); 
in Chemistry—Chemical Lecture Diagrams, Dr. 
G. Martin; The Wonderland of Modern Chem- 
istry, Dr. G. Martin, illustrated (Sampson Low and 
Co., Ltd.); Elements of Physical Chemistry, J. L. R. 
Morgan, new edition (New York: J. Wiley and Sons, 
Inc.); in Engineering—Modern Practice in Tunnel- 
ling, D. W. Brunton and J. A. Davis; Subaqueous 
Foundations, C. E. Fowler; Influence Lines for the 
Determination of Maximum Moments in Beams and 
Trusses, M. A. Howe (New York: J. Wiley and Sons, 
Inc.); in Geography and Travel—Sport and Science 
on the Sino-Mongolian Frontier, A. de C. Sowerby 
(A. Melrose, Ltd.); Hunting and Hunted in the Bel- 
gian Congo, R. D. Cooper, illustrated; South Polar 
Times, reproduced in facsimile, new volume (Smith, 
Elder and Co.); in Geology-——-A.B.C. of the Useful 
Minerals, A. McLeod; Engineering Geology, H. Ries 
and T. L. Watson (New York: J. Wiley and Sons, 
Inc.); in Mathematical and Physical Science—Science 
and Method, H. Poincaré, translated by F. Maitland 
(T. Nelson and Sons); The Stars Night by Night, 
J. H. Elgie, illustrated (C. A. Pearson, Ltd.) ; Meteoro- 
logical Treatise, F. H. Bigelow; Theory of Numbers, 
R. D. Carmichael; Elementary Theory of Equations, 
L. E. Dickson; Invariants, L. E. Dickson (New York : 
J. Wiley and Sons, Inc.); in Medical Science—Indus- 
trial Gas Poisoning, Prof. Glaister and Dr. D. D. 
Logan (E. and S. Livingstone). 
OUR ASTRONOMICAL COLUMN. 
Comet 1913f (DELAvAN).—In_ this column for 
February 12 we gave the ephemeris of comet 1913f, 
discovered by Delavan, which was computed by Dr. 
G. van Biesbroeck. This ephemeris is now con- 
tinued here for the rest of the month so far as it is 
published :— 
oh. M.T. Berlin. 
R.A. (true) Dec. (true) Mag. 
ewes iss - } 7 
MAC RU MISe<) 0.2) 47020 +5 53:6 10-7 
eae ah AQ mee 6.28:5° Se Voss 
21 wes 51 44 7 23°7 10-7 
BiGMa ot.) Qs 5A TD +8 92 10-6 
The magnitudes are based on the assumption that 
the comet was of magnitude 11-0 on December 17. 
The current number of the Lick Observatory Bulletin 
(No. 250) contains another computation of the para- 
bolic elements of this comet undertaken by Messrs. 
S. Einarsson and S. B. Nicholson, and an ephemeris 
based on those elements by Miss Julia I. Mackay and 
Mr. C. D. Shane, of the same institution. © The 
elements are very closely similar to those calculated 
by Dr. Biesbroeck, and the ephemeris differs only 
NO. 2315, VOL. 93| 
NATO LOE: 
[MarcH 12, 1914 
slightly. According to the last-mentioned computers, 
it is stated that assuming the brightness of the comet 
to have been 1-00 on December 29 of last year the 
comet may become visible to the naked eye. 
On the other hand, M. R. Goudey contributes to the 
Astronomische Nachrichten (No. 4717) elliptic elements 
of the above comet based on observations extending 
between December 18, 1913, and January 15 of the 
present year. The position he gives in his ephemeris 
for March 21 is almost identical with that stated in 
the foregoing table. 
A LarGe REFLECTOR FOR CANADA.—It is very satis- 
factory to be able to record that Canada will soon be 
equipped with a fine large reflecting telescope, con- 
tracts having been given for its construction. When 
it is mentioned that Messrs. J. A. Brashear and Co. 
will be responsible for the optical parts, and Messrs. 
Warner and Swasey Co. for the mounting, the well- 
known capabilities of these firms should certainly 
secure a fine instrument. Prof. J. S. Plaskett is to 
be congratulated on the successful issue of his en- 
deavour to secure an instrument of large aperture for 
Canada, and his account of the proposed form of 
mounting, programme of. work, etc., contributed to 
the current number of the Journal of the Royal Astro- 
nomical Society of Canada will be read with interest. 
The telescope will have a parabolic mirror of 72 in. 
clear aperture, with a central hole of 10 in., the focal 
length being 30 ft.; it is to be mounted similarly to 
the Melbourne reflector. It will be primarily used for 
spectrographic observations of stellar radial velocities, 
but it is planned to have the telescope available for 
the direct photography of nebula, clusters, etc. One 
of the principal considerations in the design is to 
enable work ‘‘to be done in the most efficient and 
convenient way possible with the simplest possible 
mechanical design.’’ The communication in question 
describes in detail the simplifications with which it is 
intended the instrument shall be equipped. 
THE SMITHSONIAN ASTROPHYSICAL OBSERVATORY.— 
The report of the Astrophysical Observatory for 1913, 
under the direction of the Smithsonian Institution, 
contains a good account of progress made; in fact, 
the director, Mr. Abbot, refers to the work of the 
observatory as ‘“‘uncommonly successful.’’ We notice 
that for the solar work at Mount Wilson there has 
just been erected a Tower telescope, 4o ft. high, for 
use with the spectrobolometer, for the study of the 
distribution of radiation over the sun’s disc. The 
report states many results of the year’s work. Thus 
the mean value of the solar constant of radiation at 
the earth’s mean distance from the sun, from about 
700 observations made at high and low stations be- 
tween 1902 and IgI2 is 1-932 calories per square centi- 
metre per minute. The fluctuation of the ‘‘ solar con- 
stant ’’ values is attributed to the variability of the 
sun, and in addition to the periodicity due to sun-spots, 
there is another ‘irregular, non-periodic variation, 
sometimes running its course in a week or ten days, 
at other times in longer periods and varying over 
irregular fluctuations of from 2 to 10 per cent. of the 
total radiation in magnitude.’”’ Further, a combina- 
tion of the effects of sun-spots and volcanic haze is 
put forward as explaining the principal outstanding 
irregularities in the temperature of the earth for the 
last thirty years. Finally, in the Californian expedi- 
tion, in which sounding balloons were employed, the 
solar radiation values at very high altitudes indicate 
that the direct pyrohelion metric observations gave 
results of the same order of magnitude as the solar 
constant work of 1902-12 by high and low sun observa- 
tions on homogeneous rays, according to Langley’s 
methods. 
