health required that his observations should be much less frequent. Much of the time after 1811 he was absent, and his work at home consisted largely in arranging the results of his previous labors, and in computations connected with them. All through the years 1814 to 1822, Herschel's health was very feeble. The severe winter of 1813-14 had told materially upon him. In 1814, however, he undertook to repolish the forty-foot mirror, but was obliged to give it over.
He now found it necessary to make frequent little excursions for change of air and scene. His faithful sister remained at home, bringing order into the masses of manuscript, and copying the papers for the Royal Society.
She was sick at heart, fearing that each time she saw her brother it would be the last. In 1818 she says:
