BRIDOL is the British Sundial Society's Register of Fixed and Mass Dials, which gives detail and photographs of about 8000 fixed sundials and 3000 mass dials in the UK.
Some of these are in private gardens, but the majority are publicly available.
On a gravel pathway in the formal garden to the east of the castle there is a bronze horizontal dial by Thomas Heath of London who was working from 1720-1753 or later. It is an elaborate dial showing the hours IV-VIII, read from the outside, divided into halves, quarters and periods of 7.5 and 1 minutes, the last numbered by Arabic numerals. In the noon gap is inscribed the word Powderham and in the centre of the dial plate is a 16-point compass rose. Place names including Rome, Constantinople, Babylon, Fort St George, Sumatra, Batavia and Pekin are engraved round the dial plate to show when noon at those places coincides with local time. There is an Equation of Time scale (described on this dial as an Equation of Natural Days). The Latitude 50°41’ is shown and there is a coat of arms and a motto. The dial is mounted on a stone pedestal of circular section with a square base and octagonal capital.
