possess of one of the most original thinkers who has appeared in this country. Except a few obituary notices in various periodicals, no biography of Sir William Herschel exists, except the short one by M. Arago prefixed to this paper, and in this case the whole is comprised within a dozen pages of the little volume in which it appeared, and these are mostly devoted to an analysis of his work.
We propose to give such particulars respecting Sir William Herschel's life as may serve to appreciate the new light thrown upon his character by the journals and letters of his sister. But it is evident that the authoress of the memoir has materials at her disposal much more ample than any to which persons beyond her family circle can have access; and we cannot but wish that she had herself performed the task. If the present volume were at some future time remodelled, so as to include the life of Sir William Herschel as well as that of his sister, it would fill a blank much felt by those interested in the history of astronomy. Although it is acknowledged that Sir William Herschel occupies the second place among English astronomers, it is not likely that he will become the subject of a separate biography. We think this, partly from the nature of his work, and partly from the character of his life. He wrote nothing but papers for learned societies, and his communications to learned societies were hardly more than transcripts of entries in the inexhaustible observation-book at Slough. The work he produced was new, but, from its very novelty, imperfect. Sir William Herschel was obliged to invent the instruments and fashion the materials he used. His object was more to traverse a large field of observation than to strive after minute details. He knew that his inventions would be improved upon, and the imperfections of his work be corrected, but he had taken possession of a domain in science opened out by himself, and full of wonders absolutely new; he was eager to push his daring investigations deeper and yet deeper in the abyss whose marvels had never been seen by the eye of any mortal man till they were unveiled to him. To linger on such a road longer than was absolutely necessary would have been for him waste of time; to dwell on trifles would have been but labour lost; and he was too good a mechanic to force effort beyond the point at which it ceased to be effectual. It is in astronomy as in another field of exploration. The footsteps of the pioneer settler in a new land are soon effaced by the tread of his successors. They settle, flourish, improve on the spot which he painfully toiled to attain. But though he has laboured, and others have entered into his labour, to the pioneer belongs the honour and the fame. So it is with William Herschel. Sir John Herschel traversed the whole field opened by his father, besides a new one of his own. He worked on his father's lines with appliances such as had not been within his father's reach. He attained a degree of precision to which the elder astronomer laid no claim. The contrast between the father and son was such as might have been anticipated from their training. The father, untrained, or, rather, self-trained in mathematics, invented methods and pursued science as the passion of his life; but until he reached middle age his devotion to astronomy was indulged at the expense of his regular avocations, and as a relief from regular business. If one may venture to speak of such a consummate observer as a rough-and-ready astronomer, the expression is only used as contrasting him with his son. Sir John, "born under the shadow of the forty-foot telescope," was trained for an astronomer from his earliest youth. By rare good fortune, the gifts of nature enabled him to avail himself of the opportunities to which he was born. Senior wrangler of his year—a year in which the great calculator Babbage went out without even competing for the first place, Sir John developed into the first mathematician of his day. His father had learnt mathematics that he might understand astronomy; the son was carefully trained to them from a boy, and passed a long life polishing the delicate weapons which had been put into his hands. No wonder that, revising Sir William Herschel's calculations, he should have superseded his father's labours, but without diminishing his father's fame. Another reason is that
