Oct. 14, 1886 | 
by Mrs. George Quish ; a Gannet (Su/a dassana), British, pre- 
sented by Mr. J. H. Gurney, F.Z.S.; two Common Chameleons 
(Chameleon vulearis) from North Africa, presented respectively 
by Mr. Charles T. Port, F.Z.S., and Mr. T. H. Carlton Levick ; 
a Common Viper (Vifera berus), British, presented by Mr. W. 
HW. B. Pain; a Porto Rico Pigeon (Columba corensts), a Trian- 
gular-spotted Pigeon (Columba guiner), bred in the Gardens. 
OUR ASTRONOMICAL COLUMN 
M. THOLLON’s MAP OF THE SOLAR SpECTRUM.—M. 
Thollon, in the Bulletin Astronomigue for July, gives some in- 
teresting details concerning the great map of the solar spectrum 
which he presented to the Paris Academy of Sciences about a 
year ago. He had completed an earlier design in 1879, but the 
positions of the lines in it had not been determined with the 
precision he desired. He therefore resolved to go over the 
work again, and to make a chart which should represent the 
positions, breadths, and relative intensities of the lines as faith- 
fully as possible. The work has required four years of con- 
tinuous toil to carry it from A to 4, at which point M. Thollon 
now leaves it. M. Trépied proposes to carry it on to the violet. 
M. Thollon’s map shows the spectrum under four different 
aspects : as seen when the sun is ro” high, and the air contains 
but little water-vapour ; then as with the sun at 30° of altitude, 
first with the air saturated with water-vapour, and next when 
the air is very dry ; and, lastly, the solar spectrum as it would 
be seen outside our atmosphere. It is therefore easy to see 
which lines are truly solar, which due to water-vapour in our 
atmosphere, and which to dry air. M. Thollon finds the dry- 
air lines limited to the great groups A, B, and a, which M. 
Egoroff ascribes to oxygen. Besides the water lines, which are 
arranged in seven groups, M. Thollon on a single occasion ob- 
served a vast number of telluric lines between a and D, the 
special origin of which he was not able to determine. 
The measures were made with a very fine glass pointer, which 
allowed a bisection of a line to be made with great exact- 
ness, the probable error of an observation being less than 1/700 
of the interval between the D lines. The breadth of a line was 
determined by observing at what distance from its extreme 
point, the glass pointer was equal to it in breadth. The intensity 
of the lines were estimated by eye. The map, which will be pub- 
lished in the Axnales de [ Observatoire de Nice, is xaore than 33 
feet in length, and embraces more than a third of the visible 
spectrum. From the scale on which it is drawn, the number of 
lines—about 3200—which it contains, the precision of the 
measures, and the fullness of the information given concerning 
the telluric lines, it will be, that which its author has striven to 
make it, the fullest and most perfect chart of the spectrum yet 
published. One of the chief purposes which it will serve will be 
to afford information as to the occurrence of changes in the 
spectrum, and M. Thollon shows by a diagram of the spectrum 
between B and C that we have strong reason to suspect that 
several lines have greatly altered in intensity since the date of 
2 
Angstrém’s famous chart. 
Comet FInrAy.—Mr. Finlay, of the Cape of Good Hope 
Observatory, discovered a comet on September 26. It appears 
to be probably identical with Comet 184q I., its elements being 
given by Dr. Holetschek as follows :— 
T = 1886 Noy. 22°6821 Berlin Mean Time. 
° ‘ a“ 
7-2 = 299 14 21 
2 = 48 35 55> Mean Eq. 1886'0. 
2= eno 
log g = 0°08793 
Ephemeris for Berlin Midnight 
1886 R.A. Decl. Log a Log x Bright- 
ese ° 1 ness 
Oct. 19 18 8 10 26 40°2S. 0°1442 O°1249 1°37 
28 to 2052) 2603359) O'I4IO O'II73 1°44 
Ayal) Ome 20) 2252 01378 O'II05 1°50 
BI 18 Sr 6 26 4°7'S. 0O°1347 O11044 157 
The brightness on September 26 is taken as unity. 
New Minor PLANET.—A new minor planet, No. 260, was 
discovered by Herr Palisa at Vienna on October 3. 
New Comet.—A new comet was discovered by Mr. E. E. 
Barnard on October 4. It was independently observed by Dr. 
Hartwig on the following night. October 5, 16h. 2m. G.M.T., 
NATURE 
579 
R.A. toh. 37m. 24s. ; Decl. 1° 3’ N. 
It is described as bright 
and round. 
Daily motion + r°5s. in R.A., and + 3’ in Decl. 
THE PULKOWA OBSERVATORY.—M. Struve has issued his 
Annual Report for the year ending May 25, 1886. During the 
year the fundamental determinations of star places for 18850 
were rezularly persevered in with the great transit instrument 
and the vertical circle. With the former Herr Wagner and his 
assistants, Wittram and Harzer, observed 4785 transits. With 
the exception of 110 observations of the sun these refer exclu- 
sively to the 383 Pulkowa fundamental stars. With the 
vertical circle Herr Nyrén obtained 739 complete observations, 
including 105 observations of the sun. The fundamental decli- 
nation determinations for 1885 would be almost completed, had 
not Herr Nyrén wished to repeat the observations with a rever- 
sion-prism eye-piece attached to the instrument in order to 
investigate certain systematic discordances. Herr Romberg, 
observing with the meridian-circle, obtained during the year 
4359 observations, chiefly of stars with large proper motion, 
comet stars, &c. The great 30-inch refractor has been intrusted 
to Hermann Struve, and has been employed in observing the 
fainter double stars of Burnham’s catalogues, the satellites of 
Mars, Saturn, and Neptune, the Maja nebula (discovered photo- 
graphically at Paris), and Mova Andromed, which was easily 
visible on January 27. M. Struve speaks-in terms of the highest 
approval of the instrument, both as regards its optical power and 
as regards the mounting, the movement of the dome, &c. The 
15-inch refractor has been used by H. Struve for obtaining 
micrometer measures of the brighter satellites of Saturn. He 
has obtained 42 comparisons of Japetus with Titan, 4o of Titan 
with Rhea, and 23 of Rhea with Dione. Herr Backlund has 
continued in charge of the 4-inch heliometer, and has measured 
with it the relative positions of Jupiter’s satellites, for a determi- 
nation of the mass of Jupiter, and of the orbits of the satellites. 
He. has also undertaken a series of measures to determine the 
parallax of Bradley 3077, which has a large proper notion, In 
the physical department of the Observatory Herr Hasselberg. 
using a Steinheil objective of 50 mm. aperture and 1°5 m. focal 
length, in combination with two bisulphide of carbon prisms, has 
succeeded in obtaining excellent photographic images of the 
solar spectrum. Between wave-lengths 4000 to 4227 on 
Angstrom’s scale, he was able to count some 650 lines, whereas 
Vogel’s map gives but 450 in the same space. During the 
course of the year 140 sun pictures were taken on 110 days. 
ASTRONOMICAL PHENOMENA FOR THE 
WEEK 1886 OCTOBER 17-23 
(7 OR the reckoning of time the civil day, commencing at 
Greenwich mean midnight, counting the hours on to 24, 
is here employed.) 
At Greenwich on October 17 
Sun rises, 6h. 29m. ; souths, rh. 45m. 24°2s. ; sets, 17h. 2m. 3 
decl. on meridian, 9° 20’ S.: Sidereal Time at Sunset, 
18h. 46m. 
Moon (at Last Quarter on October 20) rises, 19h. 15m.* ; souths, 
2h. 55m.; sets, 1oh. 42m. ; decl. on meridian, 16° 55’ N. 
Planet Rises Souths Sets Decl. on meridian 
. m, h. m. h. m, ater 
Mercury VRAOK Wiaeel2USque tenye E22 14 33S. 
Venus ... Bie) cn eA 16 50 3 32S. 
Mars . 10 45 14 43 18 41 22 45S. 
Jupiter... BORQe cy alIeohenss “LONS5S (3) Sb 
Saturn .. + 205 TAM SES Gee ee CST OO 21 19 N. 
* Indicates that the rising is that of the preceding evening. 
Occultations of Stars by the Moon (visible at Greenwich) 
Corresponding 
Oct. Star Mag. Disap. Reap. aoe a at ae 
inverted image 
h. m. h, m Ae 
ys.) LIT Lauri peu LOL 24pccg 2OmLe 69 240 
fe... 107) Lauri Speen Ecin LNs wle)anna HUNG aaa She) GIL 
BR) .c: BuA- ©. 3538.0 Gk tne (OSS) uss EE23y teen 400274) 
23 ... 44 Leonis wep OL) teeeis 2ielOme. EZ ES OMT 44a oy L 
Bee: BuAUC: 3562) 05 One 2) Auer 2) AON ene nat] 1208 
c h. A 
BO sis Vi Saturn in conjunction with and 3° 16’ north 
of the Moon. 
21 4 Mercury at greatest distance from the Sun. 
22 21... Venus in conjunction with and o° 18’ north 
of Jupiter. 
