CHAPTER XVIII.
ECLIPSE—VISITS OF SCIENTIFIC MEN—LIFE AT NAPLES—DARWIN'S BOOKS—REMARKS ON CIVILIZATION—FINE AURORA BOREALIS—DEATH OF HERSCHEL—SUMMER AT SORRENTO—BILL FOR PROTECTION OF ANIMALS—NINETY-SECOND YEAR—LETTER FROM PROFESSOR SEDGWICK—GRAND ERUPTION OF VESUVIUS—LAST SUMMER AT SORRENTO, PLANTS FOUND THERE—CONCLUSION.
The summer of 1870 was unusually cool; but the winter has been extremely gloomy, with torrents of rain, and occasionally such thick fogs, that I could see neither to read nor to write. We had no storms during the hot weather; but on the afternoon of the 21st December, there was one of the finest thunderstorms I ever saw; the lightning was intensely vivid, and took the strangest forms, darting in all directions through the air before it struck, and sometimes darting from the ground or the sea to the clouds. It ended in a deluge of rain, which lasted all night, and made us augur ill for the solar eclipse next day; and, sure enough, when I awoke next morning, the sky was darkened by clouds and rain. Fortunately, it cleared up just as the eclipse began; we were all prepared for observing it, and we followed its progress through the opening in the clouds till at last there was only a very slender crescent of the sun's disc left; its convexity was turned upwards, and its horns were nearly horizontal. It was then hidden by a dense mass of clouds; but after a time they opened, and I saw the edge of the moon leave the limb of the sun. The appearance of the landscape was very lurid, but by no means very dark. The common people and children had a very good view of the eclipse, reflected by the pools of water in the streets.
Many of the astronomers who had been in Sicily observing the eclipse came to see me as they passed through Naples. One of their principal objects was to ascertain the nature of the corona, or bright white rays which surround the dark lunar disc at the time of the greatest obscurity. The spectroscope showed that it was decidedly auroral, but as the aurora was seen on the dark disc of the moon it must have been due to the earth's atmosphere. Part of the corona was polarized, and consequently must have been material; the question is, Can it be the ethereal medium? A question of immense importance, since the whole theory of light and colours and the resistance of Encke's comet depends upon that hypothesis. The question is still in abeyance, but I have no doubt that it will be decided in the affirmative, and that even the cause of gravitation will be known eventually.
At this time I had the pleasure of a visit from Mr. Peirce, Professor of Mathematics and Astronomy, in the Harvard University, U.S., and Superintendent of the U.S. Coast Survey, who had come to Europe to observe the eclipse. On returning to America he kindly sent me a beautiful lithographed copy of a very profound memoir on linear and associative algebra. Although in writing my popular books I had somewhat neglected the higher algebra, I have read a great part of the work; but as I met with some difficulties I wrote to Mr. Spottiswoode, asking his advice as to the books that would be of use, and he sent me Serret's "Cours d'Algèbre Supérieure," Salmon's "Higher Algebra," and Tait on "Quaternions;" so now I got exactly what I wanted, and I am very busy for a few hours every morning; delighted to have an occupation so entirely to my mind. I thank God that my intellect is still unimpaired. I am grateful to Professor Peirce for giving me an opportunity of exercising it so agreeably. During the rest of the day I have recourse to Shakespeare, Dante, and more modern light reading, besides the newspapers, which always interested me much. I have resumed my habit of working, and can count the threads of a fine canvas without spectacles. I receive every one who comes to see me, and often have the pleasure of a visit from old friends very unexpectedly. In the evening I read a novel, but my tragic days are over; I prefer a cheerful conversational novel to the sentimental ones. I have recently been reading Walter Scott's novels again, and enjoyed the broad Scotch in them. I play a few games at Bézique with one of my daughters, for honour and glory, and so our evenings pass pleasantly enough.
It is our habit to be separately occupied during the morning, and spend the rest of the day together. We are fond of birds and have several, all very tame. Our tame nightingales sing very beautifully, but, strange to say, not at night. We have also some solitary sparrows, which are, in fact, a variety of the thrush (Turdus cyaneus), and some birds which we rescued from destruction in spring, when caught and ill-used by the boys in the streets; besides, we have our dogs; all of which afford me amusement and interest.
Mr. Murray has kindly sent me a copy of Darwin's recent work on the "Descent of Man." Mr. Darwin maintains his theory with great talent and with profound research. His knowledge of the characters and habits of animals of all kinds is very great, and his kindly feelings charming. It is chiefly by the feathered race that he has established his law of selection relative to sex. The males of many birds are among the most beautiful objects in nature; but that the beauty of nature is altogether irrelative to man's admiration or appreciation, is strikingly proved by the admirable sculpture on Diatoms and Foraminifera; beings whose very existence was unknown prior to the invention of the microscope. The Duke of Argyll has illustrated this in the "Reign of Law," by the variety, graceful forms and beautiful colouring of the humming birds in forests which man has never entered.
In Mr. Darwin's book it is amusing to see how conscious the male birds are of their beauty; they have reason to be so, but we scorn the vanity of the savage who decks himself in their spoils. Many women without remorse allow the life of a pretty bird to be extinguished in order that they may deck themselves with its corpse. In fact, humming birds and other foreign birds have become an article of commerce. Our kingfishers and many of our other birds are on the eve of extinction on account of a cruel fashion.
I have just received from Frances Power Cobbe an essay, in which she controverts Darwin's theory,[18] so far as the origin of the moral sense is concerned. It is written with all the energy of her vigorous intellect as a moral philosopher, yet with a kindly tribute to Mr. Darwin's genius. I repeat no one admires Frances Cobbe more than I do. I have ever found her a brilliant, charming companion, and a warm, affectionate friend. She is one of the few with whom I keep up a correspondence.