Nov. 3, 1881] 
NATURE 
19 
OUR ASTRONOMICAL COLUMN 
THE BINARY STAR y VIRGINIS.—Dr. Doberck has recently 
determined the elements of this star from all the measures avail- 
able up to the spring of the present year. He gives two orbits, 
the second of which represents the measures about the peri- 
astron-pa:sage somewhat better than the first, but otherwise has 
no material advantage over it. Dr. Doberck points out that the 
part of the orbit most interesting to examine was described 
between the years 1839 and 1847, when the angle of position, 
after being very oblique, passed quickly through zero, without 
very much alteration of distance. He finds that the correction 
required by the angles observed by Dawes, who used a prism 
for the purpose of keeping the images of the stars apparently 
in the great circle passing through the zenith, did not much 
change ; those of M. Otto Struve altered in a most pronounced 
manner ; but he adds, ‘‘it is quite natural that the errors should 
be rather large in the case of these stars, which for most obser- 
vers were at no great distance from the southern horizon, and 
which, in most telescopes, appear as large disks, at least when 
the state of the atmosphere is not exceptionally favourable.” 
Dr. Doberck gives a separate comparison with the observations 
of the Pulkowa astronomer from 1840 to 1874 both as uncor- 
rected and with the corrections in the ‘‘ Observations de Poul- 
kowa,” vol. ix. ; he finds that ‘‘the observed distances are 
improved by the corrections, except before 1843, when no cor- 
rections ought to be applied,” and this is apparent from his 
investigations on the elements of other double-stars: the angles 
also are confirmatory, but would be better without the correc- 
tions as late as 1853. We subjoin Dr. Doberck’s second orbit, 
and for the sake of comparison the orbit deduced by Thiele, 
after a very full discussion of the measures up to the year 1865, 
taken from his treatise published at Copenhagen in 1866, 
‘ Doberck. Thiele. 
Periastron passage ... ... ... 18367450 . 1836°685 
INIELAS? he Ean aoe conn coor 46 0 35 3 
Periastron from node on orbit (A) 273-55 283 44 
Inclination ce 6) 1) 35 6 
Eccentricity ... ... 0°89040 0°89575 
Semi-axis major 3°94 a 3°97 
Period of revolution 179°65 years &: 185"Or years. 
We have added 180° to Dr. Doberck’s element (A), to accord 
with the angle as it was expressed by Dawes and most other 
observers until within a recent period, but there appears to be 
slight variation in the brightness of one of the conponents, as 
will be seen from an inspection of M. Otto Struve’s observations 
in the Pulkowa volume referred to above. 
THE TRANSIT OF MERCURY, NOVEMBER 8.—This is a phe- 
nomenon of which we must look for particulars from observers 
in Australia: it will be wholly invisible in Europe, the con- 
junction in R.A. taking place at oh. 38m. a.m, Greenwich time. 
At the next transit on the mornins of May Io, 1891, the egress 
only will be observable at Greenwich, the sun rising at 4h. 19m., 
and the last external contact occurring at 4h. 5om. The condi- 
tions are reversed in the following transit on November 10, 
1894; the first external contact will take place at 3h. 55m. p.m., 
and the sun’s upper limb will be in the horizon at 4h. 18m. 
This will be the last transit of Mercury in the present century. 
Comet 1881 f (DENNING).—-M. Schulhof of Paris has 
found elliptical elements for this comet: the period assigned 
is 7} years, but is yet uncertain. A near approach to the orbit 
of the planet Jupiter is shown by M. Schulhof’s ellipse in helio- 
centric longitude 219°°7, at which point the distance is only 0°18 
of the earth’s mean distance from the sun. 
GEOGRAPHICAL NOTES 
Mr. JAMES JACKSON, ‘‘ Archiviste-Bibliothécaire” of the 
Paris Geographical Society, has published, in a volume of 
340 pages, a ‘‘Liste Provisoire de Bibliographies Géogra- 
phiques Spéciales.”” The list was undertaken at the instance 
of the Society, and was priated in some haste, we believe, for 
the recent Venice Congress. But when we remember that the 
list is only a bibliographical one, a list of lists, in fact, the accu- 
mulation of geographical literature is almost appalling. It bears 
evideice of extensive and careful research, though the author 
admits that it is by no means exhaustive. Mr. Jackson recently 
visited the United States to search the libraries there, and the 
result is a work invaluable to all students of geography. He has 
wisely devoted comparatively small space to Europe, because, 
as he states, the works relating to the countries of that continent 
are well known and easily accessible. Mr, Jackson gives not 
only bibliographies proper, but references to works on travel 
and geography, and to periodicals, journals, and transactions, 
which contain special lists. The divisions of the list are :— 
Europe, Asia, Africa, America, Oceania, Polar regions, Oceans 
and Hydrography, Peoples and Nations, Voyages, Travellers, and 
Geographers, and Generalities. By means of the arrangement 
under each division the methodical table of contents, the index 
to authors and periodical publications, the work is rendered 
easily concultable. It reflects the greatest credit on Mr, Jack- 
son’s industry, and on the enterprise of the Paris Society. 
THE only new paper in the Geographical Society’s Proceedings 
is Mr, William Beardall’s on his exploration of the Rufiji River 
under the orders of the Sultan of Zanzibar, which lasted from 
December 8, 1880, till February 19, 1881, and, we believe, was 
undertaken mainly at the suggestion of Sir John Kirk. A sketch 
map of the river accompanies the paper, on which the portion 
above Mpembeno, almost to E. long. 37°, is given from Mr. 
Beardall’s surveys. The geographical notes furnish some par- 
ticulars respecting the Italian Antarctic Expedition, Mr. Joseph 
Thomson’s recent exploration of the Rovuma district of East 
Africa, and the American Missionary Expedition to the Bihé 
plateau in West Africa. There are obituary notices of the 
Visconde Duprat, the Rev. F. W. Holland, Major S. Anderson, 
R.E., Sir Vincent Eyre, and Col. T. G. Glover, all of whom 
had rendered more or less important services to geography. 
WRITING on a new map of the Dutch East Indies, about 
to be published at the Hague, the 4umales de Pextréme Orient 
for October mentions that, besides its scientific value, this ma» is 
interesting from the adventures which have attended its produc- 
tion. The four stones which together form the lithograph were 
engraved for the most part in Java, the orography and the names 
alone remaining to be done in Europe. They were carefully 
packed and despatched to Holland by one of the Dutch mail 
steamers, but the latter unfortunately was wrecked, and the 
stones sank to the bottom of the sea. After much trouble the 
huge cases containing them were raised, and ultimately arrived 
at their destination. The new map is ona scale of I to 500,000, 
and is in three colours: the mountains in bistre, the seas, lakes, 
&c., blue, and the remainder in black. The leaves measure 218 
centimetres by 78. 
IN an ‘‘ occasional note” on Monday, the Pall Mall Gazette 
predicts a miscellaneous Arctic meeting for the opening of the 
Geographical Society’s session on November 14. If this should 
prove correct, it is to be hoped that Capt. Gray may be induced 
to give some verbal information on his discovery that the Polar- 
pack was this summer six degrees nearer the shores of Europe 
than in 1879. Though the note in question is, no doubt, to 
some extent inspired, we believe the evening’s programme is by 
no means finally decided upon, The subject on which the presi- 
dent, Lord Aberdare, in his address would most naturally dilate, 
would be his recent visit to Venice, in which case we may hope 
for an intelligent and intelligible account of the proceedings of 
the Geographical Congress. Hitherto we have heard of little 
but some effusive speeches and the showering of diplomas and 
medals on the foreign societies and individuals who took the 
trouble to send articles to the Exhibition. 
WITH reference to the report that Mr. Gordon-Bennett is 
about to visit Dundee in order to purchase a whaler to be sent 
in search of the Heanmnette, it is probable that this new expe- 
dition is the one which Lieut. Hovgaard, of the Vega, has 
volunteered to lead. 
Carr. MEYER, of the German schooner Phenix, at Callao, 
from San José de Guatemala, reports having discovered a new 
island. According to advices received by the West India Mail 
it is in Jat. 7° 48’ S., long. 83° 48’ W., lying about 188 miles 
from Punta Aguja, which is the nearest land. The island 
appeared of volcanic origin, not being over fifty feet above the 
sea in its highest part. It is a mile long, and about the same 
widrh, and Her Majesty’s ship A7zgfisher and the United States 
vessel Alaska have been despatched to examine it. The Chilian 
transport C/z/e has also been ordered to pay it a visit during a 
trip she is now making to the North, 
Mr. JosEPH THOMSON has returned to Zanzibar from a three 
months’ exploration of the I.oende tributary of the Rovuma 
