Musing from the Museum 33

A Striking Timepiece

An article by Dr Martin Blake

In the entrance hall of the museum of Spalding Gentlemen’s Society (SGS) stands a rather fine timepiece set in a tall wooden case. On closer examination it becomes clear that this is no normal clock, as the face has three additional dials besides those indicating the passage of hours and minutes. These are marked ‘Date of the Month’, ‘The Moon’s Age’ and, intriguingly, ‘The Influence of the Moon on the Waters’.

The inscription above these indicates that it was made by a certain Wm Bothamley of Kirton. The Bothamleys were a well-known family of clockmakers in and around Boston from the 18th through to the early 20th century. William, who was born in about 1715, seems to have founded the firm, no doubt after a lengthy apprenticeship with an established clockmaker. He died in 1759.

The lowest dial, ‘The Influence of the Moon on the Waters’, shows the state of the tides, in this case at Fosdyke. The first bridge over the Welland at this point was of wood and not completed until 1815 (a model can be seen in the SGS museum; some timbers from the original have been re-used to form a covered walkway at Baytree Garden Centre.) It was replaced by an iron bridge in the early 20th century. Prior to the first bridge, cattle drovers and other travellers needed to know at what time of day it was safe to cross the treacherous channels in that area, and the markings on the dial indicate whether the tide is ebbing or flowing (‘Reflux’ and ‘Flux’), and the periods of the day when it was safe and unsafe to cross. The clock is said to have stood at one time in the Old Inn in Fosdyke, doubtless a welcome stopping-off point at which to consult it, although it is possible that the inn’s landlord acquired it from an earlier owner.

Tidal clocks were produced by many clockmakers around the country, set to show the tides at local crossing places, and it did not require any great feat of calculation on their part since printed tide tables had long been in existence. Inside the door of the SGS clock is an extract from a late 18th century almanac showing times of low tide at ‘Foss Dyke and Cross Keys Washes’. Nevertheless, travellers would have needed to keep their wits about them, as the precise times of high and low tide vary a little from day to day, so that tidal clocks were always subject to a margin of error. In the North Atlantic region, because of the greater gravitational force of the moon relative to the sun, they are at their most accurate around the full and new moon.

As well as being a conversation piece, the tidal clock is a reminder of how far people in previous centuries were at the mercy of forces of nature. In some areas, the shifting sands and the rapid ebb and flow of the tide around the Wash present significant dangers to the unwary even today. Our timepiece represents an early attempt to use science, craftsmanship and ingenuity to tame those same forces of nature.

© Martin Blake