With Sir John Herschel’s survey of the Southern Hemisphere it may be said that his career as an observing astronomer came to a close.  He did not again engage in any systematic telescopic research.  But it must not be inferred from this statement that he desisted from active astronomical work.  It has been well observed that Sir John Herschel was perhaps the only astronomer who has studied with success, and advanced by original research, every department of the great science with which his name is associated.  It was to some other branches of astronomy besides those concerned with looking through telescopes, that the rest of the astronomer’s life was to be devoted.

To the general student Sir John Herschel is best known by the volume which he published under the title of “Outlines of Astronomy.”  This is, indeed, a masterly work, in which the characteristic difficulties of the subject are resolutely faced and expounded with as much simplicity as their nature will admit.  As a literary effort this work is admirable, both on account of its picturesque language and the ennobling conceptions of the universe which it unfolds.  The student who desires to become acquainted with those recondite departments of astronomy, in which the effects of the disturbing action of one planet upon the motions of another planet are considered, will turn to the chapters in Herschel’s famous work on the subject.  There he will find this complex matter elucidated, without resort to difficult mathematics.  Edition after edition of this valuable work has appeared, and though the advances of modern astronomy have left it somewhat out of date in certain departments, yet the expositions it contains of the fundamental parts of the science still remain unrivalled.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