Page:Popular Science Monthly Volume 39.djvu/641

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GLASS-MAKING.
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pot. The glass-blower dips his blowpipe into the molten mass of glass, withdrawing a small quantity of the material with his pipe. The plastic mass is rolled into a pear-shaped ball on the marvering table. A little air is then blown into the center of the

Fig. 4.—Blowing Thermometer-bulbs.