Volltext Seite (XML)
MARCI 30, 1883.J THE PHOTOGRAPHiC NEWS. 201 public know something about the ancient history of the world in reasonable time ? If the truth be told, however, we believe it will be found that the photographic resources and appliances of the British Museum are very limited, and are by no means what they should be. Professor Hofmann, the well-known chemist, has con ceived a most ingenious way of demonstrating that there is no loss of matter or weight attending the phenomenon of combustion. He burns a small piece of phosphorus in a crucible at the end of a glass tube, placed in a flask, the phosphorus being ignited by a small piece of heated copper, which, with the rest of the apparatus, is adjusted on a balance. The flask is fitted with a stop-cock and tube, and a small quantity of the air is exhausted before the burning begins. The weight before and after combustion is found to be precisely the same ; and if, after the experiment, the stop-cock is opened and air is permitted to rush in, the flask weighs actually more than before. The last meeting of the Royal Astronomical Society was a remarkable one from a photographic point of view. Dr. Gould, who has been very successful at Cordova with stellar photography, exhibited a series of enlargements from negatives of some forty or fifty star clusters. These negatives were successful in showing stars down to the 10th or 11th magnitude, and, with the aid of the micro meter, will be used for purposes of star measuring. Equally interesting as showing the important part which photography now plays in astronomy, was Mr. Common’s photograph of the Great Nebula in Orion, taken on the 30th January last with a 3-feet reflector, and an exposure of thirty-seven minutes. Mr. Common’s opinion was that it was evident photography would give the means of registering the details as well as the relative brightness of different parts of the nebulae better than the most careful hand-drawings. In the course of the discussion which ensued, the question was asked whether it was possible to determine the relative brightness of stars by photography, seeing that the photographic impression was different for different cclours of light as seen by the eye. To this Mr. Common could only say that he had never taken photographs of any strikingly coloured stars which would offer the only satisfactory test. It is satisfactory to find, as showing the accuracy of photographic astral observa tions (on which some doubt has been cast), that the magnitudes of the stars in both Mr. Common’s and Dr. Draper’s photographs of the nebula have been found to correspond very well with the magnitudes arrived at by the ordinary means. The application of photography to wood-blocks for pur poses of wood-engraving is still somewhat unsatisfactory. There are many tolerable methods known, the best of which we have published in these columns ; but engravers and publishers are always on the look-out for better. A plan recently devised by Mr. Henderson deserves their attention. The great thing to avoid is the presence of a film upon the face of the box-wood, which peels off when the graving-tool touches it, and in the specimens sub mitted to us by Mr. Henderson, this film is almost entirely absent, albeit he gets his result by floating a collodion image upon the surface of the box-wood. The key of Mr. Henderson’s plan is to employ alcohol instead of water in fixing the image on the wood. A collodion transparency is taken, detached from the glass, and put into a bath of alcohol; the wood block is likewise immersed, and the two brought into contact. In these circumstances, the wood does not swell, as it would in water, and the collodion film sinks very deeply into the wood. Moreover, if the collodion film is of a pulverulent nature and not of a horny description, there is but the least trace of a film. What land possesses the widest range of natural beauty ? The subject is one of some interest to the landscape photographer, or rather we should say to the tourist photographer, and we have heard it discussed at various times with a good deal of spirit. The best opinion we remember, was one pronounced some years ago at a cosmo politan table d’hote at the Hotel Roseg at Pontresina—we took, by-the-bye, a little photograph of that table d’hote with the rows of serviettes neatly laid for dinner—and the opinion was given by a travelled American. He pro nounced in favour of Erance. His neighbour, an English lady, did not agree at all; where was the fine scenery, for instance, between Calais and Paris all along the Chemin de Fer du Nord ? she asked. But the American quietly held his own, and in the end proved his case. One after another he recounted the natural charms of France—the wild rocky coast of Brittany, the green Normandy orchards, the forest slopes of the Pyrenees and the Vosges, the olive groves beside the blue Mediterranean, the green banks of the Seine and Rhone, the glaciers and snowy peak of Mont Blanc, the vineyards of Auvergne. It was only in the matter of lakes that French scenery was defective, concluded the American critic; but still she could claim half the lake of Geneva and tiny lakelets in Savoy and in the Pyrenees. Patent Entelligence. Grants of Provisional Protection. 896. John RUDOLF Mbihe, of 2, Laurence Pountney Hill, in the city of London, for an invention of “ Improvements in the production of printing plates or blocks by photographic means.” —A communication to him from abroad by Julius Allgeyer and Carl Bolhoevener, persons resident at Munich, in the king dom of Bavaria.r—Dated 19th February, 1883. 1007. James Henry Habe and Henry Jambs Dale, both of Little Britain, in the city of Loudon, for an invention of “ Improved apparatus for supplying sensitive plates in photo graphic cameras.”—Dated 24th February, 1883. Patent Void through Non-payment of Duties. 1054. John Chadwick and William Isaac Chadwick, both of Manchester, in the 1 county of Lancaster, Engineers, for an