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206 THE PHOTOGRAPHIC NEWS. [May 1, 1868. further experiment. Its cause remains to be ascertained, and possibly removed. Another detail may be mentioned. After passing through the various manipulations, and being sub jected to the action of the various solutions in taking a negative, the pellicle acquires a somewhat opalescent appear ance in place of its former perfect transparency. This effect continues on spontaneous drying, but disappears on the application of heat. We may here mention an ingenious application which Mr. Woodbury has for some time contemplated making of such a material as this. He proposes to sensitize a long strip of it by some trustworthy dry process ; and, providing a camera with a couple of rollers, wind off from the supply roller sufficient for a negative. After exposure this would be wound on to the other roller, and a fresh supply at the same moment brought opposite the lens for further use. The compactness and convenience of such an arrangement will be readily understood. The working out of such an arrangement is a matter of detail which we need not discuss here. The exact nature of the material and its mode of prepa ration are, of course, M. Marion's secret; but as photo graphers rarely like to work with materials of the constitu tion of which they know nothing, we may state at once that there is very little doubt that the basis of this fabric is collodion; and although it is named vitrified india-rubber, it is very doubtful whether india-rubber enters at all into its composition. The strong and peculiarly characteristic smell of castor oil is one of the first characteristics which came under our attention in examining the pellicle. On treating it with benzole it remains unaltered. It is at once penetrated by ether, and softened, but, like collodion films under such circumstances, not readily dissolved. It burns in the rapid explosive manner of pyroxyline, leaving a little sticky residue like burnt oil. Dr. Vogel described in our pages about year and a half ago the “ leather collodion” of Herr Grune, made from plain collodion containing four per cent, of soluble cotton and three per cent, of castor oil, and this appears to bo a substance of a similar constitution. Dr. Vogel proposed to supplement a film of the leather collodion with a layer of india-rubber in certain cases, and he describes the films so prepared as very solid and a little elastic. The object for which the preparation was then proposed was the transfer of negatives, ft appears pro bable that to M. Marion has occurred the happy thought of expanding this idea, and forming a transparent fabric in sheets ready for use, which will have a variety of valuable applications. Whatever the precise nature of material em ployed, the skill with which it is prepared, and the beauti fully transparent, tough, and flexible pellicle produced, confer a boon on photographers generally. PHOTOGRAPHY AND THE ABYSSINIAN EXPEDITION. Wb are in receipt of intelligence concerning the staff of photographers attached to our army in Abyssinia. From a private letter, which left that country on the 20th March last, and has been considerably delayed in transmission, we learn that Serjeant Harrold, Royal Engineers, the chief photographer, has been remarkably successful in the fulfil ment of his very laborious and difficult duties. His labours commenced at Aunesley Bay, where a large panoramic view, on three negatives, was taken of the pier, shipping, store houses, &c. As soon as this had been completed, he was at once ordered up the country to Senafe, views of the mountain passes being, obtained en route; and here he remained with his staff for a short time, taking extensive photographic sketches of the camp and environs. From .Senafe he moved forward with the first brigade of the army, accompanying General Merewether on some of his exploring expeditions, and obtaining views of the country which considerably facili tated the construction of maps and plans required for the Quarter-Master General’s Department. Serjeant Harrold I speaks in high terms of the equipment with which he was supplied, and especially of the packing thereof. In enume rating the many difficulties with which he has had to con tend, and more especially with regard to the carriage of the apparatus, he says :—“ Two of our mules had a regular dance round the camp one day, with a couple of our boxes dragging behind them. One of them rolled over on his back three times whilst carrying two of our plate-boxes, and afterwards fell down a place called the Devil’s Staircase. I am sur prised the equipment has stood so well as it has, and I think Mr. Meagher deserves great credit for the substantial manner in which he fitted it up, for it has been exposed to all weathers, merely covered with some tarpaulins.” As regards operating, Serjeant Harrold tells us he has been very much troubled with the dust blowing into the dark tent, and, inasmuch as the country is in some parts exceed ingly dry, and no rain has fallen for three or four years, the amount of dust everywhere is very considerable. The water has been very good throughout, but at times it was remark ably scarce. The collodion he took out with him perfectly fulfilled his expectations. He says :—“ I am surprised the collodion stands the test of the campaign so well; I must say that both Thomas’s and Rouch’s work first-class, and give me no trouble whatever.” All the stores and chemicals have been found to work well, and, with the exception of some of them running rather short, there is nothing whatever to complain about. It is the difficulty of transporting the apparatus and fragile paraphernalia over bad roads and paths of the rudest de scription which constitutes the chief obstacle to be overcome, not to mention the unpleasantness of being obliged to find one’s way from one out-of-the-way place to another, unac companied by a guide, and unprovided with an escort. At no time, however, was it necessary to leave the dark tent and baths behind, and there was no occasion, therefore, to employ the dry plates with which Sergeant Harrold had provided himself in case of emergencies. Besides the reproduction of landscape views, the chief photographer had likewise to exercise his functions pretty frequently in taking portrait:. Groups of the different native chiefs surrounded by their suites, of the Prince of Tigre, of Kassai, and many other, dusky warriors, had to be taken ; and when, as in some instances, these gentlemen refused to be operated upon except under the shelter of a dark bell tent, the task of producing a picture with the sun shining full into the camera was by no means an easy one. Other interesting subjects for the camera were not wanting, as shown in the following:— “ I have had an opportunity of obtaining a few photo graphs of an Abyssinian bible, which I believe is about four hundred yeais old; it is rather an odd-looking book, the leaves being of parchment of a dirty yellow colour. My copies, however, give a very good idea of the original, and show well the rude sort of paintings contained in the book. I copied two portions of the Gospel of St. Mark, and likewise a' cross belonging to a convent at Goona Goona. I was left behind with four men to complete some prints and to copy these articles, and found myself, when 1 had done, eighteen miles from the main body, in an unknown district, without a guide. We went a considerable distance out of our way before we again fell in with our troops, and then found out that we had marched in the wrong direction and had arrived at the wrong camp.” Sergeant Harrold certainly appears to bo the right man in the right place, as combining within himself the qualities of a skilful photographer and the power of readily accom modating himself to any circumstances. PANORAMIC STEREOSCOPE. Wb have had brought under our notice a new form of stereoscopic picture and stereoscope, projected by Mr. W. H. Warner and Mr. Robert Murray, which, for a large class