viii Burnham: General Catalogue of Double Stars 
Many of the stars in these two lists, discovered in the last twenty or thirty years, have shown 
rapid motion, and it is probable that a good many new orbits can be investigated in the near future, 
if these stars, which are generally of the close and difficult class, are properly followed with the 
micrometer. 
INDEXES 
The index to the new stars discovered since Struve needs no explanation. These stars will be 
readily found by their numbers in Part I. The shorter and minor discoveries are given at the end 
in alphabetical order. The Struve stars are easily found in the catalogue or in the notes, except those 
which from precession or supplemental numbering are shifted from the regular numerical order, and 
these are given in the index with the corresponding general number in the catalogue. 
As the prominent naked-eye stars are generally referred to by the constellation letters and 
numbers, and not by the corresponding double-star number, an index, with the constellations 
arranged in alphabetical order, is essential to the rapid finding of these stars in the catalogue with- 
out a knowledge of their right ascensions. Only the bright stars which are known by the Bayer 
Greek letter, or the Flamsteed number are given in the list. The few other doubles in the catalogue 
which are as bright as the sixth magnitude, but not included in the Flamsteed numbers, are not 
given, as they would necessarily be referred to by the double star lists from which they are taken. 
These large stars appear in column 8 of the catalogue with the magnitudes assigned by the 
respective observers. In the index to the constellations the photometric magnitudes are given from 
the Harvard and Potsdam observations. 
In this connection attention should be called to the careless and incorrect way in which the 
Bode constellation numbers are frequently printed in prominent astronomical publications. That 
number should always follow the name of the constellation, while the Flamsteed number should 
precede it. This correct method was established at least three-fourths of a century ago, but in recent 
years many writers have made no distinction, and have thus given the name of an entirely different 
star from the one referred to. Many of the double stars in this catalogue have the same Flamsteed 
and Bode numeral, as for example: 
ii Aquilae 2 2424 No. 8940 
Aquilae n =2 2411 8878 
20 Pegasi = H 289 11428 
Pegasi 20 = 2 2799 1 1 oo i 
9 Cygni = H 1493 9470 
Cygni 9 =2 2496 9185 
1 8 Cygni = 2 2579 9605 
Cygni 18 =2 2522 9305 
49 Cassiopeiae = /? 785 1051 
Cassiopeiae 49 = 2 30 205 
32 Herculis = ft 878 7677 
Herculis 32 =2 2024 7553 
In certain parallax observations of 2 2486, that star is often called 6 Cygni, in spite of the facts 
that 6 Cygni is one of the prominent stars of this constellation, is a double star of another class, and 
is more than 20 distant from the other. The Bode catalogue is no longer used for reference, but it 
is desirable to retain these numbers used by the old observers; and to avoid error and confusion they 
should be written as they were by these astronomers. 
PRECESSION TABLES 
It has been suggested that for the convenience of many persons who may use this catalogue, 
it would be desirable to add precession tables. Even if the limits of the page in Part I had per- 
mitted giving this information for each star, it would obviously be much better for all practical uses 
of the catalogue to give this in the present condensed form, which is sufficiently exact for the cer- 
tain identification of every object in the sky, and in other star catalogues. 
The tables for precession in right ascension (from o to 60 declination) are taken from 
the compilation and arrangement printed in Publications of the Washburn Observatory, Vol. I. The 
