Ronald Lee, The Knibb Family: Clockmakers, Byfleet, 1964; Dawson, Drover & Parkes, Early English Clocks, Woodbridge, 1982; Tom Robinson, The Longcase Clock, Woodbridge, 1981; Antiquarian Horological Society, Horological Masterworks, Whitstable, 2003; J.A. Neale, Joseph and Thomas Windmills, Woodbridge, 1999; Percy G. Dawson, The Iden Clock Collection, Woodbridge, 1987
The present clock is unusual in a number of respects, some of which have led to the conclusion that its dial plate may be a replacement. It has the most unusual feature of an alarm function. This is found relatively rarely on English longcase clocks and there are no other recorded examples of Knibb longcases with alarm work, although he certainly included alarms on his signature hooded wall clocks (see Lee pp.64-65, pls.59 & 60) and on some table clocks (Lee p.85, pl.81 and p.91, pl.90). Other known longcase clocks with alarms include: a Daniel Quare (Dawson, Drover & Parkes p.235, pl.315), a thirty-hour movement by Andrew Prime (Dawson, Drover & Parkes, pp.224-225, pls.299-301), a Thomas Johnson (Robinson p.149), a thirty-hour longcase by Thomas Tompion (Masterworks, pp.166-167) and two examples by Windmills (Neale pp.49 & 51). None of these clocks have spring-powered alarm trains, as on the present clock but are weight-driven, as one might expect on a longcase clock. Interestingly, the alarm mechanism on the present clock, whilst replaced in parts, does clearly include early elements and some comparison may be made with the ratchet work of a John Knibb table clock shown by Lee (p.129, pl.140).
There are several anomalous features to the dial plate. The signature is very well executed and convincingly in the style of Knibb but it is, unusually, slightly off centre. The matting to the dial centre is notably crisp, more so than one would expect to see on a clock dial of this age, and does not quite extend under the alarm-setting disc, leaving an unadorned line. To the rear there is also evidence of a number of filled holes, although it may be noted that none of these are of a type to correspond with another movement having been fitted to this dial plate or of it having been used on another clock. The plate itself is notably thin, but of itself this is not significant. Interestingly, the spandrels have been sand cast, are well finished and bear close comparison with examples by Knibb. The short trident half hour markers on the chapter ring may be likened to those on other Knibbs, such as one in the Iden collection (Dawson p.145).
The movement itself displays all the features one associates with those by Knibb and may certainly be attributed to his workshop. Of particular note are the typical Knibb delicate pillars and slender plates; it is also fully latched, in keeping with the best workmanship of the period. The latches may be compared to those on a longcase movement illustrated in Dawson, Drover & Parkes (p.207, pl.276). The figure 8-shaped aperture on the back plate for the crutch may also be compared with one on Dawson, Drover and Parkes.
The case has undergone restorations, notably to the hood, but again is in a style one would expect from Knibb. Importantly, the bracket on the backboard aligns with the position of the bracket on the movement, whilst to the rear of the backboard one can see old nail positions which align with holes to the rear of the movement seatboard.