INTRODUCTION. 
The General Catalogue of 6188 stars herein contained is the result of an 
attempt to deduce for those stars the most accurate positions and motions that are 
readily attainable from the means at command. Computation of the motions has 
been the primary aim of this work. Putting the results in the form of a star- 
catalogue for the epoch 1900 is a natural method of exhibiting these results and is, 
apparently, the most useful way in which they could have been presented; but 
it has not been at any time the first consideration. 
The accuracy attained, while governed in the first line by the supply of good 
observations that have hitherto been made upon these stars, in a very important 
degree has also been limited by practical considerations as to the amount of com¬ 
puting that has been available. The liberal support of this work by the Carnegie 
Institution has somewhat modified this point of view, so that the question has vir¬ 
tually been: what amount of computing can be wisely and economically devoted 
to this object — how much is it worth while to expend ? 
The computations for this catalogue are intended to be practically exhaustive 
(so far as these stars are concerned) of the meridian-observations of precision which 
have been made from the time of Bradley to the present and that have been col¬ 
lected in star-catalogues of comparatively superior accuracy or extent. Such zone- 
observations as those of Lalande, Bessel, Argelander, Lamont, and others, were 
omitted from the computations as lacking in the precision requisite for the present 
purpose. There were also excluded many series of observations (mostly found in 
periodical publications) that contain only a small number of stars — partly because 
of the small return in proportion to the labor involved in the use of such catalogues, 
and more particularly because of the difficulty of ascertaining the systematic cor¬ 
rections that such catalogues may require. Strictly zodiacal catalogues were not 
included in the computations because, among other reasons, even without them, the 
motions of the stars within the zodiacal region can usually be determined with 
greater precision than those of similar classes of stars without that region — because 
many of the star-catalogues of earlier dates are more complete in the neighborhood 
of the zodiac. A list of the catalogues of observation employed in the construction 
of this work is given later in this Introduction. 
Many years have passed since there has been available for the use of astron¬ 
omers a general catalogue of stars founded upon the combined results of all 
the principal catalogues of observation. Heretofore the General Catalogue of 8377 
Stars by Francis Baily, published by the British Association for the Advancement 
of Science in 1845, has constituted the first and last attempt of this kind to col¬ 
late the results of meridian-observations upon the stars in a large and compre¬ 
hensive way. Evidently designed to facilitate the progress of meridian-astronomy 
in practical ways, it speedily came into general use as a work of reference of very 
great utility. It was probably not designed by its author as a basis of further investi- 
