Green’s Dictionary of Slang

(UK Und.) a turnpike gate; thus dub at the knapping-jigger, to pay at the turnpike gate.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 238: dub at a knapping-jigger a collector of tolls at a turnpike-gate.
1834		(con. 1737–9) W.H. Ainsworth Rookwood (1857) 268: Turpin treated him as he had done the dub at the knapping jigger.
1859		Hotten Dict. of Modern Sl. etc. 57: KNAPPING-JIGGER, a turnpike gate; ‘to dub at the knapping-jigger,’ to pay money at the turnpike.
1864, 1867, 1870		Hotten Sl. Dict. [as cit. 1859].
1873		Sl. Dict.
1895		C. Crowe Aus. Sl. Dict. 42: Knapper Jigger, a turnstile gate.