FEBRUARY 12, 1914] 
result is doubtless due, in a great measure, to the 
efforts of the director of the department, who has 
taught his fellow-countrymen that the preservation of 
the natural beauties of their country for future genera- 
tions is a national and a patriotic duty. 
THE STUDY OF THE STARS.1 
ae object of the American Association is the 
advancement of science. Thissis a very different 
matter from the diffusion of human knowledge. The 
universities and colleges provide liberally for the latter 
subject, but neglect the former almost entirely. 
Science is advanced by many individuals who hold 
offices in the universities, but seldom as a part of their 
official duties. Few professors are allowed to regard 
research as a portion of their college work, and still 
less frequently are appropriations made, or funds pro- 
vided for original investigation. Astronomy is almost 
the only exception to this rule, and even here, in 
general, the time of the officers is mainly devoted to 
teaching. | Observatories devoted to research, like 
Lick, McCormick, and Harvard, are supported by 
funds given specifically for their use, and receive 
little or no aid from the general funds of the univer- 
sities with which they are associated. It is probable 
that American universities. devote one hundred times 
as much money to the diffusion of human knowledge 
as to its advancement. The great progress made in 
America in some departments of astronomy is due 
to the fact that certain wealthy men and women have 
been willing to give large sums of money for this 
object. No other country is so fortunate in this 
respect, although in recent years, in Germany, large 
appropriations are being made by the Government for 
similar purposes. ee 
The income of certain funds, like the Elizabeth 
Thompson, Bache, and Watson funds, are also avail- 
able, but while these are of the greatest value in 
aiding particular individuals, the amount is too small 
to advance materially the entire science. The large 
funds which might aid individual research are. un- 
fortunately employed for other purposes. Scarcely any 
appropriations have been made to women from these 
funds. One of the greatest needs of science in 
America is a fund of moderate size, capable of aiding 
the men of real genius. The number of such men is 
not large, and a judicious distribution of a few 
thousand dollars annually would probably yield greater 
results than could be attained in any other way. 
A visit to Europe last summer in order to attend 
the meetings of two national and two international 
astronomical societies, enabled me to visit several of 
the larger observatories and to interchange views with 
the leading astronomers of the world. I have accord- 
ingly selected as my subject for this evening, ‘‘The 
Study of the Stars,”’ and I shall endeavour to transmit 
to you the latest views, as well as the history, of this 
department of human knowledge. It is my wish to 
present to my professional friends certain facts of a 
technical nature, and at the same time to make them 
clear to those of my hearers who have no previous 
knowledge of the subject. Astronomy has been called 
not only the oldest of the sciences, but that which 
has conferred the greatest benefits on man by render- 
ing international commerce possible. While this may 
be true of the past, the value of the astronomy of the 
present day lies in its extension of human knowledge 
and enabling the mind of man to traverse fields which 
until recently appeared to be hopelessly beyond his 
ken. 
1 Address delivered at the Atlanta meeting of the American Association 
for the Advancement of Science, December, 1913, by the retiring president 
Prof. E. C. Pickering. : re ae 
NO. 23II, VOL. 92] 
NATURE 
673 
The first catalogue of the stars was made by 
Hipparchus about B.c. 128, and was inserted - by 
Ptolemy in the ‘‘ Almagest,”’ for fourteen centuries the 
authority in astronomy for the world. This catalogue, 
which contained more than a thousand stars, gave 
both their positions and brightness. The earliest copy 
that is known: of the Almagest is in the ‘* Bibliotheque 
Nationale” in Paris. It is a beautiful manuscript in 
uncial characters of the ninth century. The other later 
manuscripts unfortunately differ from it and from each 
other, so that there is some uncertainty regarding 
two-thirds of the stars, owing to errors of copying. 
A careful study of these discrepancies has been made 
by Dr. Peters, of Clinton, and Mr. Knobel, of Lon- 
don. Each spent several years on this work, and all 
the papers are in the hands of Mr. Knobel. He is 
now preparing the entire work for publication, and it 
is hoped that it will be in the hands of the printer in 
a few months. 
A manuscript of nearly the same age is in the 
library of the Vatican, and this year a revised edition 
of it has been published. If we had a correct copy of 
the original work, it would have a great value at the 
present time. Half a century ago it would probably 
have given the best existing values of the proper 
motions of the stars which it contained, but recent 
observations enabled us to compute their positions in 
the time of Hipparchus, more accurately tham he could 
observe them, assuming that the motion was recti- 
linear. This work, however, throws light on a pos- 
sible curvature of the motions. The observations by 
Hipparchus of the light of the stars have a value that 
will be considered later. 
The first accurate measures of the positions of the 
stars were made in the middle of the eighteenth 
century. ' The catalogue of Bradley in 1755 is even at 
the present time one of the best means of determining 
the early positions of the stars.. A large number of 
similar, but later, observations by Hornsby are still 
unpublished. During the next hundred years the 
meridian circle, which is at present the standard in- 
strument for determining the places of the stars, was 
gradually evolved. In this instrument a telescope is 
mounted so that it will point only to stars in the 
meridian, that is, to stars exactly north or south of 
the observer. The declinations of stars, correspond- 
ing to the latitude of points on the surface of the 
earth, are then measured by a finely graduated circle. 
Owing to the motion of the earth all stars cross the 
meridian twice during every twenty-four hours. The 
right ascension, corresponding to longitude, will be 
given by the time of transit. At first, this time was 
found by the ‘“‘eye and ear’’ method in which the 
observer counted the ticks of an accurate timepiece 
and compared them mentally with the instant at which 
the star appeared to cross a wire in the field of view 
of the telescope. About the middle of the nineteenth 
century a great advance was made by recording the 
time electrically on a chronograph. This method was 
known for many years as the ‘“‘American”’ method, 
owing to its introduction and general adoption in this 
country. This continued to be the standard method 
almost to the present time, and an enormous number 
of observations have been accumulated in this way, 
the total cost amounting to millions of dollars. 
Perhaps the most valuable work of this kind is that 
of the Astronomische Gesellschaft, which, by inter- 
national cooperation, secured accurate observations of 
the positions of one hundred and sixty-six thousand 
stars. All stars of the ninth magnitude, and brighter, 
north of declination —23°, are included. Of the 
twenty zones, seven were observed in Germany, four 
in the United States, three in Russia, one each in 
Algeria, Austria, England, Holland, Norway, and 
