The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Amyl Acetate                                                  Anaglyph
Amyl Acetate (Ger., A?nylacetat; Fr., Acetate d'amyle ; Ital., Acetato a'amile). Synonym : Essence
of Jargonelle pears. A colourless liquid with a fruity smell. It is insoluble in water, but soluble in all proportions in alcohol and ether. It boils at 1380 C, and burns with brilliant flame, which is, however, richer in the more refrangible rays than the violet. It is used in the amyl-acetate lamp (q.v.); also as a solvent of pyroxyline in the preparation of celluloid and celluloid varnish.
Amyl-Acetate Lamp. This instrument was devised in 1884 by Hefner-Altenek, and was adopted by the International Congress of Photography in Paris in 1889 as a convenient standard light for photographic purposes. Amyl acetate is burnt in it with a cotton wick, the internal diameter of the wick tube should be 5 mm., and the height of the flame 25 mm. 1 cm. from the axis of the flame is placed a thin metal chimney, in which is a small aperture 4 mm. broad and 30 mm. long, and this can be shifted up and down so as to bring it opposite the brightest part of the flame. The amyl acetate should have a constant boiling point of 1380 C, and be free from acetic acid and water. The spectral composition of the flame is similar to that of a candle, and compared to the English standard candle, setting the amyl-acetate lamp as =1, the candle = 1-140. All metallic parts of the lamp should be made of fine silver, as the fluid so corrodes brass and other metals as to render them useless.
Anaglyph, Anaglyphoscopein the sense of back;
A means of producing stereoscopic effect due to MM. Louis Ducos du Hauron and DAlmeida. One picture of the stereoscopic pair is printed in red and the other in a greenish-blue - at any rate, the tints must be nearly comple-mentary. As both impressions are superimposed on the same white paper, and the two unlike pictures cannot exactly coincide, a somewhat confused double image results. If this anaglyph be viewed by the anaglyphoscope - a pair of spectacles, one glass of which is blue and the other red - each eye sees only one element of the two coloured stereograms, and a stereoscopic effect is produced. The application of three-colour heliochromy to the anaglyph is a more recent advance by M. Louis Ducos du
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