At a meeting of the Berlin Academy of Sciences, held on May 31 last, the venerable Alexander von Humboldt made an interesting communication upon some observations of singular movements of fixed stars. It seems that at Trieste, January 17, 1851, between 7 and 8 o'clock P.M., before the rising of the moon, when the star Sirius was not far from the horizon, it was seen to perform a remarkable series of eccentric movements. It rose and sank, moved left and right, and sometimes seemed to move in a curved line. The observers were Mr. Keune, a student in the upper class of the gymnasium, and Mr. Thugutt, a saddler, both certified to be reliable persons. The family of the latter also beheld the phenomena, Mr. Keune, with his head leaned immovably against a wall, saw Sirius rise in a right line above the roof of a neighboring house, and immediately again sink out of sight behind it, and then again appear. Its motions were so considerable that for some time the beholders thought it was a lantern suspended by a kite. It also varied in brilliancy, growing alternately brighter and fainter, and now and then being for moments quite invisible, though the sky was perfectly clear. As far as it is known, this phenomenon has been remarked but twice before, once in 1799 from the Peak of Teneriffe by Von Humboldt himself, and again nearly fifty years later, by a well-informed and careful observer, Prince Adalbert, of Prussia.
"In the great Exhibition," the Athenæum says, "Daguerreotypes are largely displayed by the French,—as might have been expected, that country being proud of the discovery: but the examples exhibited by the Americans surpass in general beauty of effect any which we have examined from other countries. This has been attributed to difference in the character of the solar light as modified by atmospheric conditions; we are not, however, disposed to believe that to be the case. We have certain indications that an increased intensity of light is not of any advantage, but rather the contrary, for the production of daguerreotypes; the luminous rays appearing to act as balancing powers against the chemical rays. Now, this being the case, we know of no physical cause by which the superiority can be explained,—and we are quite disposed to be sufficiently honest to admit that the mode of manipulation has more to do with the result than any atmospheric influences. However this may be, the character of the daguerreotypes executed in America is very remarkable. There are a fulness of tone and an artistic modulation of light and shadow which in England we do not obtain. The striking contrasts of white and black are shown decidedly enough in the British examples exhibited in the gallery,—but here there are coldness and hardness of outline. Within the shadow of the eagle and the striped banner we find no lights too white and no shadows too dark: they dissolve, as in Nature, one into the other in the most harmonious and truthful manner,—and the result is, more perfect pictures. The Hyalotypes or glass pictures are of a remarkable character. They are but a modification of the processes of Mr. Talbot and of M. Evrard as applied to glass; but the idea of copying Nature on this material,—and, having obtained a fixed picture of the shadowed image, of magnifying it by means of the magic lantern, and thus producing a truthful representation of the original,—is certainly due to the artist of Philadelphia. Many beautiful views of the Smithsonian Institute, of the Custom-house at Philadelphia, and of churches in several cities in the United States, show the minuteness of the detail which can be obtained by the use of the albuminized glass. Amongst the professed improvements Mr. Beard exhibits some enamelled daguerreotypes, in which the permanence of the picture is secured by a lacquer."
In the Royal Geographical Society, in London, the President, regretting the undignified controversies respecting the rise and course of the Nile which had taken place, unhesitatingly expressed his conviction that no European traveller, from Bruce downwards, had yet seen the source of the true White Nile. Concerning this, we may still exclaim "Ignotum, plus notus, Nile, per ortum."
Experiments with chloroform as a propelling power, in the place of steam, are now making in the port of L'Orient; and there is reason to hope, from the success which has already attended them, that they will result in causing a considerable saving to be effected in cost and in space.
The Geological Society of France will hold its annual meeting this year at Dijon. The Congress will commence on the 14th of September.