jar

1

In the British Admiralty, 19th century – 1937, a unit of electrical capacitance equal to the electrical capacitance of a standard 1-pint glass tankard, filled with brine and covered with tin foil, forming a Leyden jar. 1 jar = 10/9 nanofarads.

The Admiralty began phasing out the jar in 1937 (by A.F.O. 1552/37¹), using the farad instead.

William S. Harris.
Philosophical Magazine, vol 4, page 436 (1834).

1. Admiralty Handbook of Wireless Telegraphy, volume 1, Magnetism and Electricity.
London: H.M.S.O., 1938.

Page A2. See also the definition in section 168.

2

In Ireland, an imperial pint of beer.

Terence Patrick Dolan.
A Dictionary of Hiberno-English. The Irish Use of English.
Dublin: Gill and Macmillan, 1998.

Page 148.