Thim′ble.
1. A frusto-conical metallic sheath used to protect the end of the finger in sewing. Seamstresses use a thimble having a rounded end with numerous small pits or indentations. Those used by tailors, upholsterers, and needle-men generally are open at the end. The name is said to have been derived from thumbell, having been first worn on the thumb, as the sailor's thimble still is. It was introduced into England from Holland in 1605, by John Lofting, who manufactured them at Islington. Thimbles of bronze, exactly like the modern, have been found at Herculaneum. The thimble is sometimes utilized as a tool-holder. The extension thimble of the dentist is a prong on the end of the thimble, used to reach into the mouth to hold the foil or a compress, while operating on the teeth The bur thimble has an open ring for the index or middle finger, and a socket attached, in which rests the end of the drill handle. The hand-shield used by sail-makers and saddlers is called a palm. Silver thimbles are made from coin-silver, cast into ingots, and rolled into sheets, from which circular disks are cut by stamping; these are then placed over a circular opening and subjected to the action of a plunger. The end, side, and rim are turned in a lathe, where they are also polished by a round steel rod dipped in oil. The ornament near the rim is impressed by means of a rapidly revolving steel wheel; a second wheel forms the ornament near the middle. A third wheel provided with points makes the indentations on the side and end The inside is then polished in a similar way to that employed for the outside. The thimbles are finally boiled in soapsuds to remove the oil, and then brushed. Iron thimbles for sewing are raised by stamping with five or six blows, between as many pairs of conical dies, which are successively more and more salient. The metal is annealed between each operation. In Paris they are made from strips of thin sheet-iron, which is punched into disks about two inches in diameter; these are heated red-hot, struck up to the required depth, then placed in the lathe, where the interior is polished, the outside turned off, the pits indented with a kind of milling tool, and a groove formed on the outside to receive the gilding. After being annealed and brightened, the inside is also gilt with a strip of goldleaf applied by the pressure of a mandrel. A fillet of gold-leaf is similarly secured in the exterior groove.2. (Nautical.) An iron ring having an exterior groove worked into a rope or sail, for the purpose of receiving another rope or a lanyard. A large eyelet.
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| Stove-pipe thimble. |
3. (Machinery.) a. A sleeve or tube through which a bolt passes, and which may act as a stay. b. A ferrule to expand a tube; specifically, a ferrule for boiler-tubes. 4. A sleeve around a stove-pipe when it passes through a wall or ceiling. In Fig. 6383, the slidingjaws in the face are capable of embracing pipes of varying sizes, and the opening is closed by a shutter; a damper is placed in the rear end.
