502 
velocity of eight kilometers per second. This 
will increase in two days to fourteen kilometers, 
and in the next two days will decrease again to 
eight kilometers. This cycle of change is re- 
peated every four days. The bright Polaris, 
therefore, revolves about the centre of gravity 
of itself and its invisible companion once in four 
days. The orbit is nearly circular and is com- 
parable in size with the moon’s orbit around 
the earth. 
This centre of gravity, and therefore the 
binary system, is approaching the solar system 
at present with a velocity of eleven and a half 
kilometers per second. A few measures of the 
velocity of Polaris made here in 1896 gave its 
approach at the rate of twenty kilometers per 
second. Part of this change since 1896 could 
be due to a change in position of the orbits of 
the binary system, but most of it must have 
been produced by the attraction of a third body 
on the two bodies comprising the four-day sys- 
tem. The period of revolution of the binary 
system around the centre of gravity of itself 
and the third body is not known, but is prob- 
ably many years. 
Both companions of Polaris are invisible, but 
their presence is proved by disturbances which 
their attractions produce in the motion of the 
bright Polaris. 
SCIENTIFIC NOTES AND NEWS. 
TueE British Association for the Advancement 
of Science has held a successful meeting at 
Dover. We publish this week the address of 
the president, Sir Michael Foster, and hope to 
be able to publish shortly some account of the 
meeting and several of the addresses given by 
the presidents of the sections. 
THE International Geographical Congress be- 
gan its meeting at Berlin on September 27th, 
with about 1200 members in attendance. Baron 
von Richthofen presided, Prince von Hohenlohe, 
the imperial Chancellor being the honorary 
president. The sections were as follows: (1) 
mathematical geography, geodesy, cartography,. 
geophysics ; (2) physical geography (geomor- 
phology, oceanology, climatology); (8) biolog- 
ical geography ; (4) industrial and commercial 
geography; (5) ethnology; (6) topical geo- 
graphy, exploring travels; (7) history of geo- 
SCIENCE. 
[N.S. Vou. X. No. 249. 
graphy and of cartography ; (8) methodology’ 
school geography, bibliography, orthography of 
geographical names. Among the Americans in 
attendance were General A. W. Greely, of the 
U. S. Signal Service, Professor W. M. Davis, 
of Harvard University, and Mr. A. L. Rotch 
of the Blue Hill Observatory. 
Ir has been decided that the Zoological Park 
of New York will be opened to the public 
either on October 18th or October 25th. 
THE commission from the Johns Hopkins 
University, under the direction of Dr. Simon 
Flexner, has returned from Manila where the 
summer has been spent in the study of tropical 
diseases. 
Mr. WALTER WELLMAN arrived in London 
on August 28th and gave at the British Asso- 
ciation an account of his Polar expedition. 
He sailed for New York on September 30th. 
THE freedom of the borough of Carnarvon 
was conferred upon Sir W. H. Preece, the emi- 
nent engineer, on September 21st. He was also 
presented by the Town Council with a silver 
casket and entertained at a banquet. 
Dr. ANTON FRITSCH, director of the zoolog- 
ical and paleontological collections of the mu- 
seum at Prag, has published in a local paper 
an account of his recent visit to America. He 
speaks in high praise of the museums, institu- 
tions and collections, and recommends younger 
men of science to follow his example and visit 
the scientific institutions of the United States. 
Dr. GEORGE A. HENDRICKS, professor of 
anatomy in the College of Medicine and Sur- 
gery of the University of Minnesota, died in 
Minneapolis on September 24th. 
Signor Marconi has been able to report suc- 
cessfully by wireless telegraphy the interna- 
tional yacht races. The messages were sent 
from the steamship Ponce to a station at Nave- 
sink Highlands. 
A TELEGRAM has been received at the Har- 
vard College Observatory from Professor 
Krentz at Kiel Observatory, stating that a 
comet was discovered by Gacobini at Nice, 
Sept. 29, 313 Greenwich Mean Time, in R. A. 
16" 26™ 32° and Dec. — 5° 10’. 
Daily motion in R. A. + 2™ 0° 
Daily motion in Dec. + 0° 10’. 
