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THE PHOTOGRAPHIC NEWS, Vol. XXVII. No. 1296.—July 6, 1883. CONTENTS. _ + -AGE he Day ofthe Eclipse at Caroline Island. By C. Ray Woods 417 Collodion Emulsion and Gelatine Emulsion 418 Glass 419 On Re-sittings 420 With the Eclipse Expeditions. By C. Ray Woods 421 French Correspondence. By Leon Vidal 422 Lightning Prints on the Human Body 423 Notes 423 Patent Intelligence 426 FACE Sensitiveness of Gelatine and of Collodion Emulsions. By H. • W. Vogel 426 On Hydrokinone as a Developer. By Edwin Banks ..42/ Photo-Lithography and Photo-Zincography. By Major J. Waterhouse, b.s.c ; 438 Correspondence 9 Proceedings of Societies 427 Talk in the Studio 435 To Correspondents 4i THE DAY OF THE ECLIPSE AT CAROLINE ISLAND. BY C. RAY WOODS. The observers of the eclipse of May 6th had, in com parison with many previous expeditions, not by any means an easy time of it. Apart from the mechanical difficulties —such as landing, for instance, and the absence of skilled labour in making preparations—there were other obstacles equally formidable. A coral island, however charming as a temporary residence, is not the place one would choose for observing a passing solar phenomenon from, if one had a choice. Choice, however, there was none ; and consider ing the few specks of land over which the moon’s shadow passed, it is rather surprising that even a place offering the facilities which Caroline Island did, should have been at our disposal. Moreover, the position of the island was very inaccurately marked on the charts. This was, fortunately, to our advantage, for the new position obtained placed us nearer the line of central totality. But to pass over, for the present, our preliminary diffi culties, and to leave them and our manner of living, &c., for a future communication, I will ask your readers to picture us in their minds’ eye on the eventful morning. On the inner side of the southern island of the little group is a wooden residence, built after the usual tropical fashion, its front facing the peaceful waters of the lagoon. Just a little to the rear of it is a large tent, containing a transit instrument, a long pendulum, and a chronograph, belong ing to the United States Coast Survey, and placed under the charge of Messrs. Preston and Brown. That tent, however, is now deserted. Mr. Preston is looking through a telescope.waiting for the first contact, and ready to note its appearance instantaneously by electric com munication with his chronograph. A few yards from the large tent is a small framework and waterpoof-cardboard hut, in which several spectroscopic cameras, under my own charge, are arranged. In front of this hut is a large siderostat, still covered with a waterproof sheet, for the sky is cloudy, and light showers more than possible. A few yards from the siderostat are the photo-heliograph and corona camera, under the charge of Lieutenant Qualtrough, U.S.N., with a seaman to assist in making the exposures. A few yards further to the west is the equatorial of Mr. Law rance, with its grating and spectroscope. Like the rest of the English instruments, its formidably looking slides are not yet in the cameras. At some little distance away is Mr. Upton, busily making meteorological observa tions, the most noticeable piece of his apparatus being a tall anemometer, its cups revolving in the breeze. In a line with the house and the coast survey tent, but at a little distance away, are the tents of Professor Holden and Messrs. Hastings and Rockwell, the intermediate space containing a telescope, spectroscope, and polariscope to be used by Messrs. Preston, Brown, Doyle, and Dixon. In a conspicuous position, in hearing of all, is the post of Mr. Fletcher, whose duty it is to call the time. A few hundred yards away is the French encampment, near another wooden residence. M. Janssen is busy with a nest of instruments, the principal one of which is a huge reflector of short focus with a spectroscope attached. There are also a polariscope, prismatic telescope, and a finder. Close by is a formidable array of large cameras with lenses of short focus and large angular aperture, taking corres ponding large plates, the object being to secure any intra Mercurial planet or planets that may be visible. M. Trouvelot is armed with a large telescope, in order to view and draw the corona, as well as to search for Vulcan during a portion of the time of totality. M. Palisa, with a tele scope of six inches aperture, has laid himself out to look for Vulcan, and Professor Tacchini is prepared for spectro scopic eye observations. In both French and Anglo- American camps, each seaman has a duty allotted him, if only to stand sentry and keep out the company of the friendly-disposed, yet, nevertheless, undesirable kanakas. At length the time of first contact arrives ; the open sky enables its appearance to be recorded ; and, to the dismay and disgust of all, thin clouds pass over the sun, and the partially-eclipsed sun peeps out now and again in the most tantalizing manner. The chances seem not of the best, but that has nothing to do with the morning’s programme and duties. Preparations continue, adjustments are made, clocks are wound, plate-holders are served out and put in position. Time is rapidly approaching—only ten minutes to wait now —adjustments are now finally made, and if anything is wrong, there are poor chances of its being corrected. The clear ringing voice of Mr. Fletcher is heard at the com pletion of each minute, and some of the photographic in struments are already in operation. One minute before totality, and time is called every ten seconds. The air is rapidly darkening, we are already hard at work, and the faint trace of sunlight that still lingers is rapidly diminish ing. “ Now!” For a moment or two we are in full swing, but then comes a little breathing space. It is not so very dark ; the house, the trees, the tents, stand out far more clearly than on a moonlight night, and we can see our companions and what they are doing perfectly well. The light is just a little uncanny, that is all, but scarcely so much so as it was in Egypt during the eclipse of ’82. We look towards the eclipsed sun. There is a perfectly black disc in the centre of a most brilliant halo or glory. The coronal streamers extend to a little over two diameters ; but they are arranged, as last year, pretty eveuly round the sun.