astronomy have left it somewhat out of date in certain departments,
yet the expositions it contains of the fundamental parts of the
science still remain unrivalled.

Another great work which Sir John undertook after his return from the
Cape, was a natural climax to those labours on which his father and
he had been occupied for so many years. We have already explained
how the work of both these observers had been mainly devoted to the
study of the nebulae and the star clusters. The results of their
discoveries had been announced to the world in numerous isolated
memoirs. The disjointed nature of these publications made their use
very inconvenient. But still it was necessary for those who desired
to study the marvellous objects discovered by the Herschels, to have
frequent recourse to the original works. To incorporate all the
several observations of nebular into one great systematic catalogue,
seemed, therefore, to be an indispensable condition of progress in
this branch of knowledge. No one could have been so fitted for this
task as Sir John Herschel. He, therefore, attacked and carried
through the great undertaking. Thus at last a grand catalogue of
nebulae and clusters was produced. Never before was there so
majestic an inventory. If we remember that each of the nebulae is an
object so vast, that the whole of the solar system would form an
inconsiderable speck by comparison, what are we to think of a
collection in which these objects are enumerated in thousands? In
this great catalogue we find arranged in systematic order all the
nebulae and all the clusters which had been revealed by the diligence
of the Herschels, father and son, in the Northern Hemisphere, and of
the son alone in the Southern Hemisphere. Nor should we omit to
mention that the labours of other astronomers were likewise
incorporated. It was unavoidable that the descriptions given to each