E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Bolt in Tun,
a public-house sign, is heraldic. In heraldry it is applied to a bird-bolt, in pale, piercing through a tun. The punning crest of Serjeant Bolton, who died 1787, was on a wreath a tun erect proper, transpierced by an arrow fesseways or. Another family of the same name has for crest a tun with a bird-bolt through it proper. A third, harping on the same string, has a bolt gules in a tun or. The public-house sign distinguished by this device or name adopted it in honour of some family claiming one of the devices mentioned above.