Whitehurst & Son sundial
Whitehurst & Son sundial
Equation of time nomogram for all 365 days of the year:
visible between March and June;
bottom left: time scale: visible between III and III o'clock
The Whitehurst & Son sundial is a horizontal sundial named after John Whitehurst , an English watchmaker and scientific instrument maker, with a pole rod as a shadow thrower. Made by Whitehurst in 1812, it is now in the Derby Museum and Art Gallery collection.
The clock was set up for latitude 53 ° 2 'North, but is transportable. Their precision is relatively high, which requires, for example, the midday change from the western to the eastern edge of the finally thick shadow thrower (pole rod) and from the western to the eastern half of the scale. Within the scale for local apparent time (LAT) is a circular time equation - nomogram mounted in two parts.
Web links
Individual evidence
- ↑ It is not a travel sundial because it cannot be adjusted to the latitude of the place of use. It can only be used in another location with the same width.
Coordinates: 52 ° 55 ′ 23.9 " N , 1 ° 28 ′ 46.2" W.