I have seen Struve’s Catalogue of Double Stars, wherein I find he agrees with your and your father’s observations.... Do not think, my dear nephew, that I would expose myself so as to say a word about these things to anybody else, but to you I cannot help letting it out when I am nettled. I must leave off gossiping, else I shall not get this letter away, in which you will find Dr. H.’s barometrical observations, which I received a few days ago.... [Sidenote: 1836-1837. _Spots in the Sun._] SIR J. F. W. HERSCHEL TO MISS HERSCHEL. CAPE OF GOOD HOPE, _Jan. 10, 1837_. MY DEAR AUNT,— * * * * * I am now at work on the spots in the sun, and the general subject of solar radiation, which you know occupied a large portion of my father’s attention. The present is an admirable opportunity for studying these things, as the sun is infested now with spots to a greater degree than ever I knew it, and they are arranged over its surface in a manner singularly interesting and instructive. The sky here is so pure and clear in our summer that it would be a shame to neglect such an opportunity of making experiments on heat, and accordingly I have been occupied in the December solstice in determining the constant of solar radiation, that is to say, the absolute quantity of heat sent down to the earth’s surface from the sun at noon, or at a vertical incidence. I do not think I have ever mentioned to you a remarkable and splendid instance of liberality on the part of His Grace of Northumberland, who has taken upon himself to defray the expenses of publishing my observations at the Cape, and that in a manner the most delicate and considerate imaginable. In consequence “my book” will appear, when it does appear, under his auspices, and I hope it will not do discredit to his munificence. This is not the only, nor the most remarkable, instance however, of his attachment to the cause of science, and his disposition to promote and support it. MISS HERSCHEL TO SIR J. F. W. HERSCHEL. _March 30, 1837._ * * * * * ... I have for the last five months been in continued fear of losing Mrs. Beckedorff (to whom I could confide all my grievances). She is worn out with a cough and breaking up of constitution, and we but seldom can come together, which is when I am able to cross the street to go to her.... I experience a daily increase of pain and feebleness, so that I am (at least during this severe weather) totally confined to my solitary home; and what is worse, my eyes will not serve me to amuse myself with reading. But what business had I to live so very long? [Sidenote: 1837. _Saturn._] FROM SIR J. F. W. HERSCHEL TO MISS HERSCHEL. FELDHAUSEN, _May 7, 1837_. [Illustration: _Fig. 1._]