File:The American Museum journal (c1900-(1918)) (17538677474).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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ANIMALS OF BLOWN GLASS By Herman O. Mueller THE technique of glass-blowing is many sided and allows con- struction of intricate and truth- ful models from life, of animals as well as of plants such as the famed Harvard glass flowers. The invention of the blowpipe at the early date of the first century before Christ, opened up an era for glass-modeling. In the process pre- vious to that time molten glass or " glass paste" had been molded free-hand over a clay form, which could be easily re- moved after the glass cooled. The blowpipe consists of an iron tube
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The blast lamp is an essential part of the equipment, but the trained eye and hand of the worker are his most important tools about one and one-half inches long and one and one-fifth inches in diameter, with the aid of which the glass paste is blown to the desired shape. The mechanical tools which the glass-blower uses have always been very simple and relatively unimportant, but the natural instruments — the eye and the hand of the worker — are of the greatest signifi- cance. The most important instrument in glass-blowing is the blast lamp. This is a very simple affair and consists of a brass tube about three-quarters of an inch in diameter and three to four inches long, into which a smaller tube is inserted. The larger tube supplies the gas and the smaller one the air. The relative quantity of gas and air is regu- lated by means of cocks attached to the tubes. A steady air pressure to increase the heat intensity of the flame is created by means of bellows, or still better by a compressed-air pump. In early times an oil lamp was used in this apparatus, and the name " lampen arbeiter" was applied to the users to distinguish them from the workers in the glass factories. In some of the European glass-blowing districts the oil lamp is still used for glass-blowing. The gas lamp however is of course far supe- rior. It naturally produces a consider- ably more powerful flame, and this makes possible the modeling of much larger objects. Other tools for glass- modeling are forceps of various shapes, scissors, carbon and iron pencils of differ- ent sizes and forms, and files. The forceps are used for handling the separate pieces of glass while being welded; the scissors are used for cutting away the superfluous glass; the carbon and iron 399

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