70 
NATURE 
[Fune 24, 1886 
WE are requested to state that the annual Students’ Coxver- 
sazione will take place at the Finsbury Technical College on 
Friday evening, July 2, commencing at 7 o'clock. A good 
exhibition of apparatus, models, and specimens has been 
arranged to illustrate the various branches of applied science 
and art comprised under the College scheme of technical 
e lucation, 
A SWEDISH geologist, Dr. H. Sjogren, is about to proceed to 
the naphtha regions on the Caspian Sea, in order to prosecute 
geological studies. 
WE have received from Messrs. Griffin and Co. the third 
annual issue of the ‘f Year-Book of the Scientific and Learned 
Societies.” It gives a brief chronicle of the work done during 
the year by the various Societies, together with the necessary 
information as to official changes. 
THE Saghalien Ainos do not exhibit the same uncouthness as 
those of Yezo ; there is a greater absence of beards and of hairy 
bodies generally. ‘lhe hue of the skin very closely resembles 
that of the Caucasian ; the foreheads are high but narrow, and 
their general bearing and facial expression denote an intelligence 
much superior to that of the Yezoines. As for the theory of an 
ethnical connection between the Ainos and the Japanese, Mr. 
Penhallow says that an examination of the pure types would not 
permit such a belief to be entertained. There is a mixture of 
the two in places, but the half-breed is as easily recognisable 
there as elsewhere in the world. The Japanese, he concludes, 
are unquestionably Mongoloid, while the facts show the Ainos 
to be physically distinct, while the best ,authorities agree in the 
great resemblance which they bear to Europeans, the prevailing 
view being that they are distinctly Aryan. 
THE additions to the Zoological Society’s Gardens during the 
past week include a Bonnet Monkey (AZacacus stnicus 2) from 
India, presented by Mrs. George Willing ; two Tcheli Monkeys 
(Macacus tcheliensis $ 2) from Jungz-ling, near Pekin, presented 
by Dr. S. W. Bushell, C.M.Z.S. ; a Wild Swine (Sus scrofa @ ) 
from Tangier, presented by Mr. John Brooks ; four Sparrow 
Hawks (Accipiter nisus), British, presented by Mr. J. Rowland 
Ward, F.Z.S. ; an Egyptian Goose (Chenalofex egyptiaca), a 
Robben-Island Snake (Coronella phocarum), a Hoary Snake 
(Coronella cama), an Infernal Snake (Boodon infernalis), a 
Rhomb-marked Snake (Psammophylax rhombeatus), a Horned 
Viper (Vipera cornuta), eight Geometric Tortoises (Zestudo geo- 
metrica), a Leopard Tortoise (Zestudo p rdalis), three Areolated 
Tortoises (Homopus areolatus) from South Africa, presented by 
the Rev. G. H. R. Fisk, C.M.Z.S. ; a Crowned Horned Lizard 
(Phrynosoma coronatum) from California, presented by Mr. S. 
Upton Robins ; a Common Viper (Vifera berus), British, pre- 
sented by Mr. W. H. B. Pain; a Tuatera Lizard (Sphenodon 
punctatus) from New Zealand, presented by Capt. R. Suther- 
land ; a Tarantula Spider (Myga/e, sp. inc.) from Bahamas, pre- 
sented by Mrs. E. Blake ; a Peruvian Thicknee (@dicn-mus 
superciliaris) from Peru, two White-backed Piping Crows 
(Gymnorhina leuconota) from Australia, deposited ; a Balearic 
Crane (Baleavica pavonina) from West Africa, purchased ; a 
Japanese Deer (Cevvas sika), born in the Gardens. 
OUR ASTRONOMICAL COLUMN 
THE ABSORPTION SPECTRUM OF OxYGEN.—About three 
years ago M. Egoroff was able to show that the great groups A 
and B in the solar spectrum were due to the absorption of 
oxygen. More recently the a band was also found to be due to 
the same gas. M. Janssen, studying the absorption of oxygen 
has now discovered that under certain conditions the gas yields 
another spectrum, composed no longer of lines easily separated, 
but of shaded bands which can only be resolved with great diffi- 
culty. This system of bands appears for moderate pressures 
much later than the spectrum of lines, but it shows itself very 
quickly with increase of the density: the two systems are so 
different that it is possible to obtain either the first without the 
second or vice versd. M. Janssen was at first unable to explain 
how it was that these bands were not visible in the solar 
spectrum when they were easily obtained by passing light 
through thicknesses of oxygen far less than the sun’s light has to 
traverse before reaching us. But further experiments showed 
that these bands did not develop in proportion to the thickness 
of the stratum of oxygen producing them, multiplied by its 
density, but in proportion to the thickness multiplied by the 
square of the density. The density of our atmosphere being 
small as compared with some of the pressures at which M. 
Janssen worked, the non-appearance of these bands amongst 
the telluric lines of the solar spectrum is readily explained. 
POTSDAM OBSERVATORY. —The fifth volume of the Pudlica- 
tions of the Astrophysical Observatory of Potsdam is occupied 
with a very careful determination, by Drs. Miiller and Kempf, 
of the wave-lengths of 300 of the principal lines in the solar 
spectrum. Four gratings were used in this inquiry—one with 
about 2500 lines to the inch, the second with 6250 lines, and 
the third and fourth with about 10,000 lines to the inch. Eleven 
normal lines were first measured with all four gratings and in the 
spectra of three or four orders with each grating, every observa- 
tion being carefully corrected for temperature, &c. The com- 
putation of the wave-lengths of the 300 lines follows, and the 
details of the reduction of the observations of the eleven normal 
lines, and a catalogue of the wave lengths of 2614 lines as given 
in the Potsdam Atlas of the spectrum, and as now corrected, 
concludes the work. The following are the wave-lengths of the 
selected normal lines, expressed in millionths of a millimetre :— 
C, 6567314, 640°035, 612°247 ; Da, 589°625, 562°475, 545°580; 
by, 517°284, 495°779, 470°321, 441°534, and 407'186. It would 
seem from these determinations that Angstrom’s wave-lengths 
require small but sensible corrections. 
THE BINARY STAR y CORON AUSTRALIS.—With reference 
to our note on this double star (NATURE, vol. xxxiii. p. 425), in 
which we pointed out the large difference in the position-angles 
computed, for the present year, from the orbit of Mr. Gore and 
from that of Mr. Downing, we may draw attention to a com- 
munication by Mr, H. C. Wilson, of the Cincinnati Observa- 
tory, printed in the Odservatory, No. 111, pp. 234-235. Mr. 
Wilson gives the mean results of observations of the binary in 
188¢ and 1883 as follows :— 
1881°72 45°53 1°38 
1883 "62 37°75 1°62 
The angles computed from Mr. Gore’s elements for these two 
epochs are respectively 47°°29 and 36°:49, which may be re- 
garded as agreeing fairly well with the observations. It 
appears, therefore, that of the two orbits referred to above, 
Mr. Gore’s is by far the most satisfactory. 
OBSERVATIONS OF THE COMPANION OF SirIus.—Prof. 
Young has communicated to the S7dereal Messenger (No. 46, 
p. 182) a series of measures of the companion of Sirius made at 
Princeton, for the most part with the 23-inch refractor, with 
powers of 460 and 300. Prof. Young remarss that during the 
present year the companion has been a difficult object, except 
when the seeing was good, and there have been fewer good 
nights than usual. The mean annual results are :— 
Position-Angle Distance 
Epoch Measure ene Epoch Measure ee 
1883'I05 ... 39°0 I 1883°105 ... 9°41 I 
1884°273 ... 36°30 5 1884°270 ... 8°70 4 
1885°112 ... 34°06 7 1885°089 ... 809 8 
1886°047 .... 29°77 4 1886°049 ... 7°59 3 
ASTRONOMICAL PHENOMENA FOR THE 
WEEK 1886 JUNE 27—FULY 3 
(FOR the reckoning of time the civil day, commencing at 
Greenwich mean midnight, counting the hours on to 24, 
is here employed.) 
At Greenwich on Fune 27 
Sun rises, 3h. 47m. ; souths, 12h. 2m. 44"Is. ; sets, 20h. 19m. ; 
decl. on meridian, 23° 20’ N.: Sidereal Time at Sunset, 
14h. 42m. 
