Green’s Dictionary of Slang

whirligig n.

1. (UK Und.) the pillory.

[UK]H.T. Potter New Dict. Cant (1795).
[UK]G. Andrewes Dict. Sl. and Cant.
[UK]G. Kent Modern Flash Dict.
[UK]Flash Dict. in Sinks of London Laid Open.

2. an unspecified gadget.

[UK]J. Manchon Le Slang.
[US]S. King It (1987) 162: ‘I’ll tell you sumpin else, if you’ll turn off y ’whirligig, there.’ I turned off my tape-recorder and smiled at him.