616 
it. Much trouble has been taken to construct a system 
which cannot easily be put out of order; and the result 
is an admirable piece of mechanism. The sizes of the 
planets, with the exception of the earth, are roughly 
to a scale of 50,000 miles to the inch. The earth is 
represented by a globe one inch in diameter, and 
additional mechanism makes the moon revolve around 
it while the earth itself traverses its orbit. The orrery 
may be moved by hand or by clockwork, which will 
keep the planets in motion for about three-quarters of 
an hour; and it is not put out of adjustment if the 
clockwork is started after the hand motion has been 
used. The planets can also be placed in any position 
in their orbits to begin with; and then when the 
clockwork is started, they will perform their orbital 
movements accurately. The satellites are carried 
round the sun with their respective primary planets, 
and can be placed in any position around them, but 
are not connected with the clockwork system. The 
instrument is mounted upon a heavy mahogany 
floor-stand, which gives stability to it, and 
it forms an attractive as well as instructive piece of 
furniture. Any attempt to represent the bodies in the 
solar system and their movements by a model cannot, 
of course, be more than a compromise, but the trouble 
taken by Messrs. Philip to produce an orrery which 
is compact and reasonably accurate is worthy of 
encouragement. 
OUR ASTRONOMICAL COLUMN. 
ASTRONOMICAL OCCURRENCES FOR FEBRUARY :— 
Feb. 3. 19h. om. Venus in aphelion. 
5. 5h. 32m. Saturn in conjunction with the 
Moon (Saturn 6° 50’ S.). 
>. oh. 39m. Mars in conjunction with the 
Moon (Mars 1° 9! S.). 
8. ioh. 38m. Neptune in conjunction with the 
Moon (Neptune 4° 31’ S.) 
11, 8h. om. Venus in superior conjunction with 
the Sun, 
A 16h. om. Saturn stationary. 
2. 13h. om. Mars stationary. 
2. 3h. 30m. Jupiter in conjunction with the 
Moon (Jupiter 2° 56’ N) 
,, 6h. om. Mercury at greatest elongation E. 
», 6h, 41m. Uranus in conjunction with the 
Moon (Uranus 2° 39/ N.). 
24. 11th. 16m. Sun eclipsed, invisible at Green- 
wich, 
,, 20h. 1m. Venus in conjunction with the 
Moon (Venus 1° 1’ S.). 
26. 6h. om. Venus at greatest heliocentric lati- 
tude S. 
28. 8h. om. Mercury stationary. 
Use OF THE OBJECTIVE PRISM IN THE DETERMINATION 
or RaptiaL Vetocit1es.—M. Maurice Hamy, who re- 
cently proposed an ingenious method of utilising the 
objective diffraction grating in line of sight work (see 
Nature, November 27, 1913, p. 383), has just pub- 
lished (Comptes rendus, No. 2, vol. clviii.) details of 
‘a way in which advantage may be taken of the supe- 
rior light power of the objective prism for the same 
purpose. In order to supply the fiducial points neces- 
sary to obtain absolute wave-lengths, M. Hamy has 
devised means whereby the stellar spectrum may be 
photographed down the middle of a comparison spec- 
trum of a terrestrial light source taken with the help 
of a collimator. Whilst the details of the instrumental 
NO. 2309, VOL. 92| 
NATURE 
[JANUARY 29, I914 
contrivances by which the stellar and terrestrial spectra 
are brought into proper coordination, as well as the 
theory of measurement and reduction of the resulting 
plates are too complicated to be described here, we 
may indicate that this adjustment is ‘secured by 
making successive images of the star and middle of 
the slit reflected by the polished and silvered base of 
the prism viewed in a second reflector near the 
camera end coincide with the point of intersection of 
two wires. The realisation of the idea should delight 
the heart of some instrument-maker. Measurement 
need not be confined to the particular star on which 
the settings are made, as M. Hamy shows that it is 
possible to utilise all the spectra registered during the 
one stellar exposure. 
A Monument To ‘‘ THE Hour.’’—The Revue Scien- 
tifique for January ro states that M. Lecornu, a mem- 
ber of the Paris Academy of Sciences, has suggested 
a proposal for the erection of a monument to “the 
hour,” to perpetuate the remembrance of the inter- 
national standardisation of the hour (March 9, 1911), 
and of the choice of Paris as the ‘centre horaire 
mondial,” and the transmission of time by the wire- 
less installation of the Eiffel Tower. A committee 
has been formed, and it is proposed to set up the 
monument at Villers-sur-Mer, a spot where the Green-' 
wich meridian cuts France; this position has been 
accurately determined by the military geographical 
service. : 
“L?’AsTRONOMIE"’ FOR JANUARY.—In the first issue 
of L’Astronomie for the current year it is announced 
that the council of the Astronomical Society of France 
has decided further to enhance the value of this very 
excellent journal by increasing the number of illus- 
trations and their scientific and artistic interest; more- 
over, the number of pages of text will be also aug- 
mented. Another new feature will be the publication 
in the journal every three months of a new series of 
celestial charts, drawn especially by M. G. Blum, 
giving the aspect of the southern hemisphere sky. 
The first of these charts is printed in the present 
number. The new form of illustration is also 
depicted, and shows striking reproductions of 
numerous images of the planet Saturn, so successfully 
photographed by Prof. Barnard in 1911 with the large 
Mount Wilson reflector. This issue contains also 
much interesting matter. Thus an account with illus- 
trations is given of the large fall of meteorites at Aztec, 
in Arizona, which took place on July 19, 1912. M. 
Camille Flammarion gives an excellent summary of 
the magnetic communication between the sun and 
earth, while the concluding article on stellar photo- 
metry is contributed by M. Jules Baillaud. Observers 
of Mars will be interested in the abnormal feature on 
this planet’s surface observed by M. Fournier in 
October and December, 1911, in the Lybian and Arca- 
dian regions. 
INTERNATIONAL CONFERENCE ON THE 
SAFETY OF* LIFE AT “SEA 
THE International Conference on the Safety of Life 
at Sea, first suggested by the German Emperor 
and convened by the British Government, has now 
held its final meeting. As a result of its labours, a 
very important convention has been signed by pleni- — 
potentiaries of the following States:—The British 
Empire, including Australia, Canada, and New 
Zealand, which were represented separately, Germany, 
France, the United States, Austria-Hungary, Italy, 
Spain, Sweden, Norway, Holland, Belgium, and Den- 
mark. The text of the convention will not be pub- 
lished until February 15, but the chairman of the 
conference, Lord Mersey, has outlined its principal 
