April 19, 1883] 
NATURE 
589. 
Pror, O’REILLY writes from the Royal College of Science 
for Ireland, Dublin, that there was visible there, on the night of 
the 16th, between 10 and 11 o’clock p.m., an aurora appearing 
as a glow, but without any beams when observed. ‘The wind 
on the 17th was from the south, but the temperature was still 
relatively low. 
THE opening of the proposed International Horticultural Ex- 
hibition and Botanical Congress at St. Petersburg has been 
postponed to May 5s, 1884. 
THE Council of the Popular Observatory of the Trocadeéro has 
decided to open a series of Sunday lectures, illustrated by expe- 
riments, during the whole of the summer season. The Thursday 
lectures will be devoted to astronomical topics and delivered in 
the evening, and will be followed by demonstrations on the sky 
itself, weather permitting. 
Dr. Doserck, whose appointment to Hong Kong we noted 
last week, has been attached to Markree and not to Dunsink 
Observatory. 
THE additions to the Zoological Society's Gardens during the 
past week include a Rude Fox (Cavs vudis) from Demerara, 
presented by Mr. G. H. Hawtayne, C.M.Z.S.; an Arabian 
Gazelle (Gazella arabica 2) from Arabia, presented by Mr. J. 
Sewell; three Weasels (AZustela vulgaris), British, presented by 
Mr. George Lang ; a Wood Owl (Syrnium aluco), British, pre- 
sented by Capt. E. Hall ; a Lanner Falcon (Fa/co /anartus) from 
Eastern Europe, presented by Major J. H. Hussey ; a Common 
Rayen (Corvus corax), British, presented by the Earl of Eldon ; 
five Mississippi Alligators (A/igator mississippiensis) from the 
Mississippi, presented by Mr. Thos. Baring; two Common 
Snakes (Z7opidonotus natrix), British, presented by Lord 
Londesborough, F.Z.S. ; two White-fronted Capuchins (Cebus 
albifrons & 9) from South America, presented by Mr. H. 
Smith ; a Palmated Newt (7Z7iton palmipes), British, presented 
by Mr. J. E. Kelsall; two Ambherst’s Pheasants (7haumalea 
amherstie § 2) from Szechuen, China, deposited ; three Lions 
(Felts leo 6° 2) from South Africa, two Reeves’s Pheasants 
(Phasianus veevest 6 9) from China, a Great Black Cockatoo 
(Microglossa aterrima) from New Guinea, a White-backed Piping 
Crow (Gymnorhina leuconcta) from Australia, a Common Otter 
(Lutra vulgaris), British, purchased. 
OUR ASTRONOMICAL COLUMN 
D’ArreEst’s COMET.—We last week referred to the discovery 
of D’Arrest’s comet at the Observatory of Strasburg on the 3rd 
inst., upon the strength of a telegram received at Lord Craw- 
ford’s observatory from Prof. Krueger, tv the following effect :— 
“Dr. Hartwig dis:overed on April 3°610 G.M.T. D’Arrest’s 
periodical comet in right ascension 13h. 55m. 24s., declination 
+8° 16’. Daily motion —44s. in R.A., and + 9’ in declina- 
tion.” This telegram was published in the Dun Echt Circular, 
No. 76, but in No. 77 issued five days later we read, ‘* Prof. 
Krueger telegraphs that the object observed by Dr. Hartwig 
was not D’Arrest’s comet but a new nebula.” The ‘daily 
motion” assigned to the object in the first telegram, notwith- 
standing its precise accordance in amount and direction with 
that which the comet would have had in that position, was 
therefore an illusion, Tne calculated place of the comet for 
April 3°610 G.M.T, is in R.A. 13h. 55m. 11s., Decl. +8° 23':6. 
During the next period of absence of moonlight for which an 
approximate ephemeris was given in this column la-t week, the 
theoretical intensity of light will be nearly one-third greater than 
on April 3. 
THE GREAT CoMET OF 1882.—Prof. Ricco sends us the fol- 
lowing observation of this comet made with the 10-inch refractor 
at Palermo :— 
M.T. 
App R.A. 
ihe) ms: he ums s: 
April 6 at 8 21 29 
5 58 5°93 
App. Decl. 
-9 4 49°2 
elongated nacleus containing two or more points. At this time 
the comet was distant from the earth 3°87, and from the sun 
3°75- 
In Bulletino della Socteta di Scienze Naturali di Palermo for 
February 8 we find some remarks by Prof. Riccd on the cireum- 
stances attending the passage of the comet through perihelion. 
On studying the appearance of the sun from twelve to fifteen 
hours afterwards, he found the prominences were by no means 
unusual either as regards number or dimensions ; there were nine 
with a greater altitude than 30”, and about as many smaller 
Ones ; the highest was one of 85” on the west-north-west limb, 
opposite to the part of the disk traversed by the comet, in which 
no prominences were visible. The comparison of observations 
made before and after perihelion passage, shows that no very 
sensible effect was produced upon the motion of the comet in its 
course through the coronal atmosphere, and Prof Ricco con- 
cludes, on the other hand, that his own observations, made a 
few hours subsequently, ‘‘possono servire a constatare che 
reciprocamente la cometa non disturhd per nulla il corso degli 
ordinari fenomeni dell’ attivita solare.” 
THE BINARY STAR # ERIDANI.—In a communication to the 
Royal Society of New South Wales in June, 1880, Mr. Russell, 
the director of the Observatory at Sydney, suggested, from the 
measures made since 1856, including his own up to 1880, that 
this object might not be a binary star at all, but merely afforded 
an instance of one star passing before another by reason of its 
proper motion. This opinion is repeated in the volume of 
double-star results obtained at Sydney, published last year. ‘‘ In 
fact,” observes Mr. Russell, ‘‘a straight line accords better with 
all the ob-ervations made subsequent to Herschel’s than any 
ellipse, and it would appear that the changes are due simply to 
proper motion ; of this I think there cannot be any doubt... .” 
The question has just been very fully and carefully considered 
by Mr. Downing, of the Royal Observatory, Greenwich, who 
arrives at an opposite conclusion to that of Mr. Russell, and 
considers ‘‘ there is not sufficient evidence to justify us in asserting 
that # Eridani is other than a binary star.” We entirely agree 
with Mr. Downing in his opinion. If we only coiwpare the 
measures made by Jacob in 1845-46, with those of Russell and 
Tebbutt, 1878-80, we get the following expressions :— 
d.sin~g = — 47361 — [8°3894] (¢ — 1850°0) 
d.cos p= + 0122 — [g'1017] (¢ —1850°0) 
showing differences from Herschel’s mean measures, epoch 
1834°996, of —5°°I in position, and + 0”°82 in distance, which 
are too large to be tolerated. 
This star has been occasionally miscalled 6 Eridani, which 
would imply that it was one of Flamsteed’s stars. Flamsteed, it 
is true, has a star which he calls 6 Eridani, and which is 
B.A.C. 926; the binary is B.A.C. 521. The letter was 
attached to the star by Lacaille in the catalogue at the end of 
his Calum Australe Stelliferum. The number 6 is merely bor- 
rowed from Bode. 
GEOGRAPHICAL NOTES 
Tue Geographical Society of Lisbon has awarded their gold 
medal for this year to Mr. Carl Bock, the distinguished eastern 
traveller, who has also been recently elected Corresponding 
Member of the Italian Anthropological Society. 
THE third German Geographentag was held at Frankfort-on- 
the-Main on March 29 in the presence of 430 men of science. 
Prof. Rein (Marburg) delivered the inaugural address, and also 
opened the geographical exhibition, which comprised 1100 
objects of interest. Amongst the most successful addresses we 
mention the following: Dr. Pechuél Loesche (Leipzig), on the 
mountain districts of the Congo River, in which he described 
minutely the mountain chains traversed by the Congo, according 
to the researches of Oscar Lenz and Gii-sfeldt. Prof. Ratzel 
(Munich), onthe significance of Polar re earch with regard to 
geographical science; he proposed a resolution, ** That the 
Geographentag recognises that the resumption of Polar research 
by the German Government is equally in the interest of geo- 
graphical science and of the German nation.” This resolution 
was adopted unanimously. Dr. Finger (Frankfort), on topo- 
graphy as an introduction to geography. Herr Mang (Baden 
Baden), on the method of the tellurium and lunarium. Dr, 
Breusing (Bremen), on the means for the determination of the 
He states that the comet was a very faint nebulosity with an | position of localities at the time of great discoveries. Dr. 
