pear gauge

English

Etymology

So called because consisting in part of a pear-shaped glass vessel.

Noun

pear gauge (plural pear gauges)

1. A kind of gauge for measuring the exhaustion of an air-pump receiver.

Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.
(See the entry for “pear gauge”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.)