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Show 150,000 Screws to the Pound. The minuteness of some of tho screws made In a watch factory may be measured by the statement that It takes nearly 1GO.000 of a certain kind to weigh a pound. Ur..er the microscope micro-scope they appear in their true characterperfectly charac-terperfectly finished bolts. The pivot ot the balance wheel Is only one two-hundredths ot an Inch in diameter, and tho gauge with which Divots are classified measures to the Ufv thousandth part of an Inch. Each jewel hole Into which a pivot fits Is about one five-thousandth of ao Inch larger than the pivot' to permit sufficient suffi-cient piny. The finest screw for a small-sized watch ban a thread, of 2C0 to the Inch and weighs one one-hundred and thirty thousandths of a pound. Jewel slabs of sapphire, ruby cr garnet are first sawed Into slabs one-fiftieth of an Inch thick, and are shellacked to plates so that they may be surfaced. Then the Individual jewnlB are sawn or broken off, drilled through tho center, and a depression made In the convex side for an oil cup. A pallet jewel weighs one one-hundredth one-hundredth and, fifty-thousandths ot a pound; a roller Jewel a little more than one two-hundred and flfty-sl thousandths. The largest round hair-Fprlng hair-Fprlng stud Is four-hundredths of a Inch In diameter and about ntne-hun-dredths of an Inch In length. |