Page:Memoir and correspondence of Caroline Herschel (1876).djvu/169

Rh have been secured and described in one minute of time."

The ten years from 1788 to 1798, although a blank as regards her personal history—the Recollections cease with her brother's marriage—were among the busiest of her life, and in the year last mentioned the Royal Society published two of her works, namely, "A Catalogue of 860 Stars observed by Flamsteed, but not included in the British Catalogue," and "A General Index of Reference to every Observation of every Star in the above-mentioned British Catalogue." It is in reference to these that she wrote the very interesting letter to the Astronomer Royal, which is given among others, in its place, in the Journal. But another work, which was not published, was the most valuable, as it was the most laborious of all her undertakings. This was "The Reduction and Arrangement in the form of a Catalogue, in Zones, of all the Star-clusters and Nebulæ observed by Sir W. Herschel in his Sweeps." It supplied the needful data for Sir John Herschel when he undertook the review of the nebulæ of the northern hemisphere; and it was for this that the Gold Medal of the Royal Astronomical Society was voted to her in 1828, followed by the extraordinary distinction of an Honorary Membership. This Catalogue was not completed until after her return to Hanover, and Sir David Brewster wrote of it as "a work of immense