S3® Dr. Herschel’s Astronomical Observations, &c. 
POSTSCRIPT. 
It will be seen that in this paper I have only considered the 
nebulous part of the construction of the heavens, and have 
taken a star for the limit of my researches. The rich collec- 
tion ofclusters of stars contained in the 6th, 7th, and 8th classes 
of my Catalogues, and many of the Connoissance des Temps, 
have as yet been left unnoticed. Several other objects, in 
which stars and nebulosity are mixed, such as nebulous stars, 
nebulae containing stars, or suspected clusters of stars which 
yet may be nebulae, have not been introduced, as they ap- 
peared to belong to the sidereal part of the construction of the 
heavens, into a critical examination of which it was not my 
intention to enter in this Paper. 
WILLIAM HERSCHEL. 
Slough, near Windsor, 
May 26, 18x1, 
