It is not necessary to say here how nobly Sir JOHN HERSCHEL redeemed the trust confided in him. All the world knows of his Survey of the Southern Heavens, in which he completed the review of the sky which had been begun and completed for the northern heavens by the same instruments in his father's hands. A glance at the Bibliography at the end of this book will show the titles of several papers by Sir JOHN, written with the sole object of rendering his father's labors more complete.
[29] He was created a knight of the Royal Hanoverian Guelphic Order in 1816, and was the first President of the Royal Astronomical Society in 1821, his son being its first Foreign Secretary.
REVIEW OF THE SCIENTIFIC LABORS OF WILLIAM HERSCHEL.
In this chapter I shall endeavor to give such explanations as will enable the general reader to follow the course of discovery in each branch of astronomy and physics, regularly through the period of HERSCHEL'S life, and up to the state in which he left it.
A more detailed and precise account, which should appeal directly to the professional astronomer, will not be needed, since ARAGO has already fulfilled this want in his "_Analyse de la vie et des travaux de Sir WILLIAM HERSCHEL_," published in 1842. The few misconceptions there contained will be easily corrected by those to whom alone they are of consequence. The latter class of readers may also consult the abstracts of HERSCHEL'S memoirs, which have been given in "_A Subject-index and a Synopsis of the Scientific Writings of Sir WILLIAM HERSCHEL_," prepared by Dr. HASTINGS and myself, and published by the Smithsonian Institution.
An accurate sketch of the state of astronomy in England and on the Continent, in the years 1780-1820, need not be given. It will be enough if we remember that of the chief observatories of Europe, public and private, no one was actively devoted to such labors as were undertaken by HERSCHEL at the very beginning of his career.
His observations on variable stars, indeed, were in the same line as those of PIGOTT; FLAUGERGUES and DARQUIER, in France, had perhaps preceded him in minute scrutiny of the sun's surface, etc.; but, even in that department of observation, he at once put an immense distance between himself and others by the rapid and extraordinary advances in the size and in the excellence of his telescopes. Before his time the principal aids to observation were the Gregorian and Newtonian telescopes of SHORT, and the small achromatics of DOLLOND.[31]