The photographic news

• Bandzählung: 35.1891
• Erscheinungsdatum: 1891
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-189100009
• PURL: http://digital.slub-dresden.de/id1780948042-18910000
• OAI: oai:de:slub-dresden:db:id-1780948042-18910000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

238 THE PHOTOGRAPHIC NEWS. [March 27, 1891. destitute of viscosity or fluid friction, whilst air is far from being such a perfect fluid. Still, the phenomena are closely enough related for our illustrative purpose. No pigmentary colours are produced in the finished photographs, which merely break up white light so as to reflect the right prismatic colours from the right places. Diffraction gratings for producing diffraction spectra have no proper colour of their own. They are merely pieces of glass or polished white metal, ruled with innumerable fine lines by means of a machine- guided diamond point; yet they afterwards break up white light, so as to yield . all the colours of the rainbow with brilliancy. THE PRIMULINE PROCESS IN COMMERCE, The primuline diazotype process, which attracted so much attention last year at the British Association and elsewhere from its refreshing novelty, has been taken over by Messrs. Watson and Son, who are about to introduce it into the regular channels of photographic trade. This news is interesting, for the process is one of which the utilitarian possibilities are, for the most part, as yet undeveloped, but are likely to be evolved when experienced photographers begin experimenting in relation thereto. Two leading features of it are, that it is excessively cheap, and produces results marked by their brilliancy and by the variety of the resulting colours. The largest class of profits is usually made by the first introduction of novelties to the public ; as processes and methods grow old, competition does its work, and cutting prices become the order of the day when the results have to be sold to the masses of the population. High-class work of any kind, however, is always likely to hold its own when the results have to be sold to the cultured class of the community, which is more com petent to judge artistic and scientific merits. Should the primuline process become a fashionable “ craze ” like that of ornamenting china, it is likely to be in great public demand. Any photographer who has transparencies of any of his sitters, can borrow their white handkerchiefs, and, with their permission, in a few minutes on a sunshiny day, present them their likenesses printed thereon in brilliant colours, and so fixed as to resist the action of hot soap and water. This is certain to attract their attention, and to send them home talking about the matter among their friends. Indeed, this primuline process seems to well deserve the attention of professional photographers. Full details about the working of the primuline process are to be found in our last YEAR-BooK. The Chicago International Columbian Exhibition, 1893. —A proclamation by the President of the United States, Mr. Benjamin Harrison, has been made to the effect that satisfac tory proof having been presented as to adequate grounds, buildings, and finances for this proposed great Exhibition for celebrating the 400th anniversary of the discovery of America by Columbus, he, in the name of the United States, declares that the Exhibition will be opened on May 1st, 1893, in the city of Chicago, Ill., and he invites all nations to take part in the commemoration. SEASONABLE PRECAUTIONS. ■ Now that this truly dreary winter, which has brought us so much snow and general discomfort, has nearly past away, we shall forget all about its cold and its cruel fogs until the dark days come round once more, when, perchance, we shall remember that it is time to commence grumbling again; but, for the present, we have something better to do, in looking forward to the speedy budding of the trees, and the general awakening of nature after her long sleep. This refreshing change in the aspect of the world is even more welcome to the photographer than it is to others, for his work, as well as his pleasure, depends in great measure Upon that same sun which causes the birds to sing and the flowers to bloom. And, in the case of out-door photography, whether it be professional or amateur in character, dependence upon the sun naturally becomes still more emphasised. Photographers, indeed, are looking forward to their first day in the field as eagerly as sportsmen of another kind anticipate with pleasure the first of September. In both cases, too, the implements of sport must be carefully overhauled to see that there is nothing wanted to mar the expected enjoyment; but, whilst the sportsman has little to do beyond seeing that his weapon is clean and bright, the photographer has to be far more particular before he can hope to win success. As a knight of old had to tty every joint of his armour before going into the lists, so must the photo grapher look most carefully to see that his apparatus has not deteriorated during its enforced period of rest. In spite of the best cabinet work—and there is little to complain of in the manufacture of cameras now-a-days— the best wood will sometimes warp after experiencing the vicissitudes of an English winter. A crack which is almost imperceptible to the eye will be quite wide enough to admit a glint of light, and such cracks will often make their appearance without apparent cause. Another weak point where light will occasionally creep in, is where the leather bellows of the camera is attached to the woodwork. Even the bellows part of the instrument itself is liable to injury, especially from the attacks of insects ; and, although we have no such destructive creatures in this country as white ants, we have the ubiquitous cockroach, which appears to be able to make havoc of, and to digest any substance, with the exception, perhaps, of cast steel. Mice, too, will nibble away at leather if they cannot find anything else with which to appease their hunger, so that the bellows of the camera has at least two pests which hanker after it more or less. There are other parts of the camera which require looking to before work is recommenced, notably the rising front, and the junction of the metal flange of the lens with the woodwork. The dark slides, too, may be of the best make, and may have proved to be reliable against ingress of light, but this is no guarantee that they will remain so for ever. A corner joint may have given way just sufficiently to admit a tiny pencil of light, which will spoil every negative entrusted to its care. All these things should