Twenty-three years ago, when first I came here, I visited Madame W. (not von) once or twice, saw her observatory and a telescope, I believe not above 24-inch focal length; at that time she amused herself with modelling the heads of the Roman Emperors: her daughter, then a girl, was a poet, and a portrait of her was exhibited as a Sappho crowned with laurels.... * * * * * The great difficulty of writing begins at last to tell in Miss Herschel’s correspondence. One more letter in 1845, is the last of the ample sheets she had been used to fill. The monthly report becomes shorter, more blotted, and betrays extreme feebleness. On the first of October, 1846, she wrote: MY DEAREST NIECE!— I must not let the messenger go without a line just to say that I am still in the land of the living, of which, however, I have no other proof than a letter from Baron v. Humboldt, inclosing a Golden Medal from the King of Prussia. I can say no more at present, and the post will not wait, so believe me, my dear niece, yours and my dear nephew’s most affectionate aunt, CAR. HERSCHEL. The following is the letter referred to from Alexander von Humboldt which accompanied the Gold Medal presented by the King of Prussia on the occasion of her ninety-sixth birthday:— [Sidenote: 1846-1847. _Letter—Baron Humboldt._] BERLIN, _Sept. 25, 1846_. MOST HONOURED LADY AND FRIEND!—