- Twaddell's hydrometer
- Twaddell Twad"dell, n., Twaddell's hydrometer Twad"dell's hy*drom"e*ter [After one Twaddell, its inventor.] A form of hydrometer for liquids heavier than water, graduated with an arbitrary scale such that the readings when multiplied by .005 and added to unity give the specific gravity. [Webster 1913 Suppl.]
The Collaborative International Dictionary of English. 2000.