THE MOON'S MOVEMENTS WRONG.—The " London Court Journal " says, Mr. Adams communicated to the Eoyal Society, at the closing meeting of their session in London, that he had discovered that the principle of Laplace's calculation of the secular motion of the moon is positively erroneous. This is a discovery which affects the whole range of lunar astronomy, seeing that all the cacula-tions made on the assumption that the moon really was in the place assigned to her, are wrong. A staff of computers will therefore havo fc to Boati wnrk ti tbft Ohservatorjzto recompute the lunar observations, avoiding" the error, which amounts to about seven seconds. We shall then have the means of rectifying our Nautical Almanac, and of making it more accurate than ever; while those astronomers, and they are not a few, who have written about ancient eclipses, will have to go over their task again, and see what they make of it with the new principle. It was said, shortly after Mr. Adams' discovery of Neptune, that such a man would find other great works to do in astronomical science, and here we have an invaluable confirmation. SCIENTIFIC ENTHUSIASM.—Professor Agas-siz could not attend the Convention lately held at Cleveland, on account of sickness caused by his researches in the rice swamps of the South. The Cleveland Herald says:— His search for things new and strange at the South was crowned with complete success; but he contracted the malignant fever of the country, from which he barely escaped with life. Among other novelties which he found there, was a fish without ventral fins, and it is related as expressive of his unextinguish-able enthusiasm in matters of science, that when slowly recovering, a friend called to see him and said fjo him, "I am sorry to hear, Professor, that you have been dangerously ill." " Ah, yes," said Professor A., " I have been very sick but no matter, I have found a fish without ventrals." PHOTOGRAPHS ON WOOD.—Drawings of this art on wood have lately been successfully produced in Manchester, England. Beautiful pictures of buildings, and perfect portraits of individuals have been drawn by sunlight upon smooth blocks of boxwood, such as are ordinarily used by wood engravers. This discovery will be of invaluable service to the latter art, as it will save the expense of employing draughtsmen to mark the blocks previous to engraving. Drafts of complicated machinery in perspective, and other complicated sketches, which require much time, expense, and skill in the preparation of blocks for engraving, can now be produced in a moment i with the light of the sun.
This article was originally published with the title "Scientific Memoranda"