File:The American Museum journal (c1900-(1918)) (17540672043).jpg

Title: The American Museum journal
Identifier: americanmuseumjo15amer (find matches)
Year: c1900-(1918) (c190s)
Authors: American Museum of Natural History
Subjects: Natural history
Publisher: New York : American Museum of Natural History
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: Biodiversity Heritage Library

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400 THE AMERICAN MUSEUM JOURNAL pencils for widening the openings in glass tubes or finished parts, and the files for cutting glass tubes and rods. No iron molds of any kind are vised for preparing glass models in the American Museum, but all parts are shaped free- hand from glass tubes and rods. Colored glass is frequently used for the colored parts, but if the desired tints and shades of glass are not available, plain crystal glass is molded into shape and the colors applied later with the brush or with an air-brush. The process of using glass as a medium for representing animals will be realized
Text Appearing After Image:
Stages illustrating the modeling in glass of the microscopic animal Gonium. These little, single-celled creatures live in colonies of sixteen together, and there may be very many such colonies in a drop of water in some degree if we follow the construc- tion of a glass model — for example, that of a colony of the protozoan Gonium. From a glass tube of about one-half inch diameter, a piece about two inches long is separated by means of the blast lamp, blown in the flame to a cuplike shape and opened out to its whole width at one end. The gas flame is brought into action on the opening and the force of the flame will by itself enlarge the opening; but if the carbon pencil is rotated inside the heated area at the top of the cup this will flange it out more quickly. To imitate the coloring seen in the living Gonium individual, which seems to shade from a deep green below to a light, almost transparent tint above, hundreds of little green glass particles are welded to the inner surface of the glass cup before it is wid- ened out, until the desired tints are secured. To do this a green-colored glass rod is broken up into small pieces and these are further ground in a mortar to the desired grain. A small quantity of these particles is strewn inside the cup which is then rotated in the gas flame until the green parts begin to fuse and ad- here to the wall of the cup. This process is repeated until the desired intensity of the color is secured. When the green particles are applied thickly the color is more intense; when scat- tered, a lighter tint results. After this the other parts of the animal such as nu-

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