An unusual sundial echoing the 3 Millennium sundials designed for the Tylers and Bricklayers company of the City of London. One of these is near the Millennium footbridge in Central London.
The gnomon is made from two brass plates with a narrow air gapp. At solar noon, when the sun is directly over head, a line of light shines through the air gap for a few minutes only. This enables the sundial to be set absolutely accurately to true north.
The polar dial is supplied with a baseplate (shown in the left-hand photo at the head of the page) which adjusts the angle of the gnomon for different latitudes as shown in the table.
|Model||Gnomon angle |
& baseplate angle
|Polar48||48° N (0°)||46° to 49° N (note A)|
|Polar50||50° N (2°)||49° to 51° N|
|Polar52||52° N (4°)||51° to 53° N|
|Polar54||54° N(6°)||53° to 55° N (note B)|
The hour lines on polar dials are parallel with the gnomon; they are indicated with Roman numerals for winter time and Arabic numerals for summer time. At 6 a.m. winter time the shadow of the oxhead gnomon just skims the left hand "ear" of the sundial, and from just before 7, the shadow has reached the left hand end of the main dialplate. At noontime, the shadow is directly under the gnomon, and at 6 p.m. it arrives at the top of the right hand "ear".
Universal Polar Spot on Sundial
- 31.5 W x 14 D x 13 cm. high.
- Suitable for all latitudes