For a discussion of 'wings' and centre swinging pendulums on English lantern clocks see George White, English Lantern Clocks, Antique Collectors' Club, 1989, pp.200-203. From the start of the Third Period of English lantern clockmaking (1660-1700) clocks with divided trains and centre swinging pendulums (as on the present example) are known. However, no written evidence of 'wings' occurs until 1913 and it seems probable that the pendulums were in fact intended to swing through rough slots in the side doors (cf. the present clock). According to White (op.cit, p.201) almost every clock with centre swinging pendulum also had alarm work.