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

shall forfeit 10 dollars for every copy of the same in his pos session, or by him sold or exposed for sale, one-half thereof to the proprietor, and the other half to the United States.” Section 9.—That section 4,967 of the Revised Statutes be, and the same is hereby amended so as to read as follows :— “ Section 4,967.—Every person who shall print or publish any manuscript whatever, without the consent of the author or proprietor first obtained, shall be liable to the author or pro prietor for all damages occasioned by such injury.” Section 10.—That section 4,791 of the Revised Statutes be, and the same is hereby repealed. Section 11.—That for the purpose of this Act each volume of a book in two or more volumes, when such volumes are published separately, and the first one shall not have been issued before this Act shall take effect, and each number of a periodical shall be considered an independent publication subject to the form of copyrighting above. Section 12.—That this Act shall go into effect on the 1st day of July, a.d. 1891. Section 13.—-That this Act shall only apply to a citizen or subject of a foreign State or nation when such foreign State or nation permits to citizens of the United States of America the benefit of copyright on substantially the same basis as its own citizens, or when such foreign State or nation is a party to an international agreement which pro vides for reciprocity in the granting of copyright, by the terms of which agreement the United States of America may, at its pleasure, become a party to such an agreement. The existence of either of the conditions aforesaid shall be deter mined by the President of the United States by proclama tion made from time to time as the purposes of this Act may require. Photographic Prints of Crystals (formed under a pressure of 1,500 atmospheres).—M. Amagat, Professor of Physics at the Faculty of Lyons, has devised an appliance which not only allows us to see the solidifying of certain bodies under consider able pressure, but also to obtain crystals that are perfectly sharp, and to photograph them. He placed under the eyes of the Academy of Sciences four directly enlarged prints of these crystals, obtained with the appliances and with the assistance of M. Donnadieu, Professor of Geology of the same Faculty. We have here a very interesting application of photography called upon to give the proof of some curious phenomena, whose existence might be contested were it not for this important mode of vision and record.—Moniteur. This Royal Institution.—The following are the lecture arrangements after Easter :—Mr. J. Scott Keltie, three lectures on the Geography of Africa, with special reference to the Ex ploration, Commercial Development, and Political Partition of the Continent ; Dr. E. E. Klein, three lectures on Bacteria : their Nature and Functions (the Tyndall Lectures) ; Mr. William Archer, four lectures on Four Stages of Stage History (the Betterton, the Cibber, the Garrick, and the Kemble Periods) ; Professor Dewar, six lectures on Recent Spectroscopic Investigations ; Dr. A. C. Mackenzie, four lectures on the Orchestra considered in connection with the Development of the Overture ; Professor Sylvanus P. Thompson, four lectures on the Dynamo ; Mr. H. Graham Harris, three lectures on the Artificial Production of Cold ; Professor A. H. Church, three lectures on the Scientific Study of Decorative Colour. The Friday evening meetings will be resumed on April 10 th, when a discourse will be given by Sir William Thomson on Electric and Magnetic Screening. Succeeding discourses will be given as follows April 17th—Professor A. W. Rucker, Magnetic Rocks; April 24 th—The Rev. Canon Ainger, Euphuism, Past and Present ; May 1 st—Mr. James Edmund Harting, Hawks and Hawking ; May 8th—-Professor W. Ramsay, Liquids and Gases ; May 15th—Professor G. D. Liveing, Crystallisation ; May 22nd—Professor J. A. Ewing, The Molecular Process in Magnetic Induction ; May 29th—Mr. David Gill, LL.D., H.M. Astronomer at the Cape of Good Hope, An Astronomer s Work in a Modern Observatory ; June 5th—Mr. St. George J. Mivart, M.D. ; June 12th—Professor Harold Dixon, The Rate of Explosion in Gases, THE BRITISH ASSOCIATION. MCETROROLOGICAL PHOTOGRAPHS. The Committee on Meteorological Photography of the British Association for the Advancement of Science, consisting of Mr. G. J. Symons, F.R.S. (chairman), Professor R. Meldola, F. R.S., Mr. John Hopkinson, F.L.S., and Mr. Arthur W. Clay den, M.A. (secretary), has issued the following circular :— Photographs are desired of clouds, lightning, hoar-frost, re markable hailstones, snow-wreaths, avalanches, glaciers, storm waves, waterspouts, tornadoes, dust-whirls, halos, parhelia, or any other meteorological phenomena or their consequences. General Instructions. 1. As soon as possible after exposing a plate, number it and fill in the details relative to it on one of the forms supplied. The more completely these are filled in, the more valuable will the photograph be. 2. The size of the plate is immaterial, provided that the focus is sharp. Use a magnifier when focussing, and for objects like clouds focus upon a distant tree or building. 3. Use a lens which does not distort the image. 4. Do not touch up either negative or print. 5. When photographing any object which is moving or changing, a series of views taken at short intervals, so as to show the progress of the phenomenon, will be of especial value. 6. Whenever possible, a figure or other object of known dimensions should be introduced, in order to serve as an approxi mate scale. Cloud PHOTOGRAPHY. For heavy clouds no special apparatus is required, but expo sure must be shorter than for ordinary landscape work. For very thin clouds exposure must be extremely short, and deve lopment very cautious. Fair results may then be occasionally obtained without special means. In order to obtain better and more certain results three methods have been adopted :— (a) Using a slow plate and rapid lens, with short exposure ; (6) using an ordinary plate and lens, but with a sheet of pale yellow glass in front of the lens ; (c) using an ordinary plate and lens, but placing a plane mirror of black glass in front of the lens so that its surface makes an angle of about 33 degrees with the axis of the lens. The image reflected in the mirror is fairly easy to photograph. The Committee hope to receive examples of each of these processes, as well as examples and descriptions of any other special devices which may be adopted by observers. Lightning Photography. When a thunderstorm occurs at night it is very easy to pho tograph the flashes of lightning. Fix the camera rigidly (do not hold it in the hand), and ex pose it to a part of the sky where flashes are frequent. As soon as one flash has crossed the field of view, change the plate. Whenever possible, count the number of seconds between seeing the flash and hearing the beginning of the thunder. Note this time on the print or form. If you have two cameras, some useful results may be attained by using one as described above, and holding another in the hand, pointing in about the same direction, but kept in con stant oscillation. It is hoped that two photographs of the same flash may be thus secured. Another desirable experiment is to fix both cameras in the same direction, change the plates in one after each flash, but leave the plate exposed in the second until six or eight flashes have crossed the field of view. If the camera is placed in a window this must be open, as the interposition of a window pane may give rise to multiple images. Be particularly careful to note the exact time and direction of each flash photographed. A rapid lens, with a stopf/8 or thereabouts, should be used for lightning. Prints, which may be mounted or unmounted, should be sent as early as possible to the Secretary, at Warleigh, Tulse Hill Park, London, S.W,