[f. TAP v.2 + -ER1.]
1. One who taps or lightly strikes: e.g., one who taps at a door, etc.; one who taps the wheels of railway carriages, to test their soundness; a shoemaker who rivets on soles and heels; a dialect name of the lesser spotted woodpecker.
1810. Splendid Follies, III. 89. If the young gentleman did not immediately return to town, and satisfy their urgent demands, a tapper would … make his appearance at Mistley.
1837. Dickens, Pickw., xxxii. A low tap was heard at the room door. Mr. Bob Sawyer … bade the tapper come in.
1883. Macm. Mag., Feb., 269. The honest tapper of every wheel [of a railway train].
1885. Swainson, Provinc. Names Birds, 99. Lesser Spotted Woodpecker (Dendrocopus minor). Also called … Wood tapper…. Tapperer,… or Tapper.
1903. Daily Chron., 11 Sept., 8/4. Boot Trade, repairs.—Smart tapper to finish on machines.
2. That which taps or lightly strikes, as a hammer for striking a bell; spec. a key in an electric telegraph which is depressed (with a tapping sound) to complete the circuit, a telegraph key; in wireless telegraphy, a device for restoring the filings to their original condition; also tapper-back.
1876. Preece & Sivewright, Telegraphy, 43. There are two forms of the single needle instrument in general use, viz. the drop-handle and the pedal or tapper form. Ibid., 47. The sending portion of the ‘pedal’ or ‘tapper’ form of single needle.
1898. Edin. Rev., Oct., 306. The restoration to the coherer of its defective efficacy is brought about by the automatic action of a ‘tapper.’
1903. Sci. Amer., 26 Dec., 483/2. In 1894 he [Sir O. Lodge] exhibited at Oxford his first ‘tapper-back,’ or automatic system of decohering the iron filings after each impulse.
