ASTRONOMY IN AMERICA. 
361 
by systematic observations so definitely ascertained this rela- 
tion as to prove beyond all manner of doubt that the bands 
are due to aqueous vapour. Unfortunately, though his results 
were published in America, they were not published in such a 
way as to attract notice in Europe, and accordingly European 
astronomers remained ignorant of the most important fact dis « 
covered by Cooke until they had rediscovered it for themselves. 
The Observatory at Ann Arbor, Michigan, was erected in 
1854, chiefly through the exertions of Chancellor Tappan, of 
the Michigan University. Dr. Briinnow, our present Astronomer 
Boyal for Ireland, was for a long time director of this observa- 
tory. It is at present under the able control of Professor 
Watson, who has added nearly a score of planetoids to the 
known members of the solar family. 
The Observatory of Dartmouth College, Hanover, N.H., 
illustrates in a remarkable way the energy and zeal with which 
college observatories are managed in America. It would be 
- difficult to name any observatory in this country where ob- 
servations of greater interest, as respects the physics of astro- 
nomy, have been made than those effected by Professor Young 
with the 9-inch telescope constructed by Alvan Clark for the 
Dartmouth College ; or than the supplementary observations 
made by Young with a powerful telescope conveyed to an ele- 
vated pass in the Kocky Mountains. Amongst his results may 
be specially mentioned — first, the observations of the most re- 
markable solar outburst yet witnessed, an outburst during 
which the glowing hydrogen of the prominences was driven to 
a height of at least 200,000 miles from the surface of the sun ; 
and, secondly, the identification of more than 250 lines in the 
spectrum of the solar sierra. 
And as the most interesting and characteristic observations 
yet made upon solar prominences are due to Professor Young of 
Dartmouth Observatory, so the most accurate and detailed 
drawings yet made of sun-spots are those by Professor S. 
Langley, of the Alleghany Observatory, near Pittsburgh. 
At Chicago, a very fine telescope, 18 inches in aperture, by 
Alvan Clark, has been erected ; but, owing to pecuniary diffi- 
culties consequent on the great fire (followed by the commercial 
depression which has recently affected the United States), 
that observatory has suffered considerably from the want of a 
properly remunerated director. The Astronomical Society of 
Chicago has done its best to set matters straight, but differ- 
ences have arisen which have marred their efforts. In the 
meantime Mr. S. W. Burnham, of Chicago, has shown admirable 
zeal and skill in the systematic observation of double stars, 
having discovered and measured more than 450 of these objects 
(all of a delicate and difficult nature). 
