962 
ASTRONOMY IN THE FIRST HALF OF THE 
NINETEENTH CENTURY. 
Dourine the first half of the present cen- 
tury the most eminent astronomers, Karl 
Friedrich Gauss, Friedrich Wilhelm Bes- 
sel and Friedrich Georg Wilhelm Struve, 
were natives of Germany. Gauss was 
born in 1777 at Braunschweig; Bessel 
in 1784; Struve in 1793 at Altona. All 
three were also mathematicians, but of 
various mathematical ability; in Struve’s 
ease his reputation in the higher mathe- 
matics was subordinate to that as an as- 
tronomer. Gauss was one of the first 
mathematicians of his age, and perhaps of 
any time. Bessel was celebrated by his 
success in the most difficult problems of 
mathematical astronomy, as well as in the 
practical handling of instruments, and as a 
teacher of the science. 
Gauss’s early ability as a calculator was 
enough to render him conspicuous in the 
circle of his friends, and to stimulate his 
relatives, people of humble station, to make 
every exertion for his education. He re- 
ceived the degree of doctor of philosophy at 
Gottingen at an early age, and became pro- 
fessor of astronomy there. His earliest 
mathematical work was the ‘ Disquisitiones 
Arithmeticz,’ in which he inserted the bril- 
liant discovery that a regular polygon of 
seventeen sides can be inscribed in the circle 
by ruler and compasses without the use of 
any means but those allowed by Euclid. 
When still a young man of twenty-four, he 
became widely known as an astronomer, by 
the rediscovery of the small planet Ceres. 
This had beén discovered by Piazzi, and ob- 
served only ashort time. After this time it 
was lost in the rays of the sun, and no other 
astronomer was able to calculate its position 
with sufficient accuracy to find it again, as 
proper formulz were wanting in the astro- 
nomical periodicals. These formule Gauss 
possessed, and they solved the problem, and 
the asteroid was readily found by the re- 
SCIENCE. 
[N. S. Von. X. No. 261. 
sults of his calculations as a star barely 
visible to the naked eye. As professor at 
Gottingen, he lived to a venerable age. 
Among his students was our eminent coun- 
tryman, Dr. B. A. Gould. Gauss fitted up 
the observatory with the best instruments 
of the time, and his works have not yet 
been published in full sufficiently to con- 
tent his surviving disciples. 
Bessel, seven years younger, was born at 
Minden; and his early education was in the 
counting house of Messrs. Kulenkamp at 
Bremen. He soon found astronomy more 
interesting than business and became well 
- known amongst specialists in that science. 
In 1814, he was made a professor and direc- 
tor of the observatory in the rising uni- 
versity of Konigsberg, which soon became 
celebrated as the piace where Bessel lived. 
Every effort was made to keep the young 
institution at the height of astronomy as 
then known. He lived there till 1846, 
when he passed away at the premature age 
of sixty-two, after many striking achieve- 
ments, among which is especially con- 
spicuous the first satisfactory measure of a 
star’s distance from the solar system. He 
showed that 61 Cygni was more than five 
hundred thousand times* the sun’s distance, 
or between forty and fifty millions of mil- 
lions of miles from us. 
Gauss lived till 1855 and died at the 
venerable age of seventy-eight, ‘ full of age 
and honors.’ His younger friend, W. 
Struve, was the son of the head master at 
Altona, whose special department was 
philology. He received his early training 
in astronomy at Dorpat, where his ability 
as a calculator attracted the attention of 
Huth, then professor there of mathematics 
and astronomy. Huth allowed him to use 
the observatory freely. He received his 
first instructions in the use of instruments 
from the ‘Observator’ Paucker. After 
*JIn treating this star I have used later figures 
than those of Bessel. 
