C 405 3 
XX. On the different methods of constructing a catalogue of fixed 
stars. By J. Pond, Esq. F. R. S. Astronomer Royal. 
Read May 21, 1818. 
In the present state of practical astronomy, the principal 
object in a national observatory, such as that at Greenwich, 
is to define the position in the heavens, of the fixed stars and 
other celestial bodies, at the moment of their passage over 
the meridian ; and we judge of the perfection of the instru- 
ments, and of the skill with which they are employed, by the 
degree of precision with which this operation is performed. 
The very great changes and improvements that have taken 
place within these few years in the instruments of this 
establishment, are well known to all persons who have 
interested themselves in its concerns. The liberality of his 
Majesty’s Government has been literally unbounded; and 
instruments of unusual magnitude and of most difficult con- 
struction, have been executed with a success that has exceeded 
the most sanguine expectation. Such powerful means 
entrusted to my care, could not but produce, on my part, a 
continued anxiety that they should be employed in the 
most advantageous manner. Being constantly under the 
necessity of reflecting a great deal on the various possible 
inodes, both of making observations and of deducing results 
from them, I have insensibly been led to adopt methods 
which differ very materially from those generally pursued, 
