The Spot-On Polar Sundial - setting up instructions

1. Level the surface where you will position the sundial so that it is as close to horizontal as possible. Ensure that the plinth is firm, so that it will not change its orientation or its level.

2. Set your watch accurately by a radio time signal.

3. Find out the time of solar noon at your location using our unique Solar Noon Calculator.

When your watch reaches the exact time of Solar Noon, rotate the polar dial until the shaft of sunlight shining through the slit in the gnomon lies exactly along the dotted noon line.

4. Mark the front edge of the polar dial with a pencil line on the plinth

Unscrew the two large bolts holding the dialplate and the backplate to the basplate

5. Mark the fixing holes through the baseplate, drill out the holes, insert a Rawlplug or similar, and screw the baseplate onto the plinth

Replace the sundial and back plate on the baseplate, and tighten up the securing screws

7. Your polar sundial is now locked on to true North for ever, and will not need any further adjustment.

8. Remember that in summer time, you read the bottom scale (Arabic numerals) and in winter, you read the upper scale (Roman numerals)