C 39 ] 
VI. Appendix to the preceding Paper on the changes which appear 
to have taken place in the declination of some of the fixed Stars. 
By J. Pond, Esq. Astronomer Royal, F. R. S. 
Read November 14, 1822. 
The observations which have been made during the last 
summer, confirm in a very decided manner the results which 
formed the subject of my last communication ; in which I 
laid before the Society the nature of the differences that exist 
between the computed places of the principal Stars of the 
Greenwich Catalogue, and those deduced from actual obser- 
vation. It is not my present intention to offer any explana- 
tion of the cause of these phenomena, although many obvious 
conjectures present themselves, the value of which it will 
require perhaps many years to determine. It is now my 
principal object to consider the force of that explanation of 
the differences in question, which will most readily occur to 
every astronomer, namely, that the whole may arise either 
from error committed by the observer, or from defect in the 
instruments of observation : this objection being the more 
weighty from the circumstance, that the observations of three 
distant periods are employed, and that an error in those of 
either period (but particularly of the two latter) would ma- 
terially affect the result now under consideration. 
I believe that every person, in proportion to his experience 
in the use of astronomical instruments, (even of the most 
unexceptionable construction ) , will be cautious in admitting 
