gnomon

Modern techniques for a replica sundial exhibit

A first trial assembly of the gnomon and base plate in position on the dial

Details for making the sundial came from archive records and photos. This image shows the design and successful first assembly of the new parts.

The replica of a 19th century lighthouse sundial we are making will be part of a mobile exhibition. It is progressing well. Lighthouse sundials were made by skilled instrument makers, who worked mainly with hand tools. We are using modern techniques for cutting out the metal and etching the intricate design on the dial plate. The picture shows our first trial to assemble the dial and gnomon parts. Continue reading

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What is the declination of the wall for a sundial

The diagram illustrates a method for calculating wall declination.

Knowing the declination of the wall (WD) is important for designing a sundial. The basic calculation is azimuth angle (AA) minus protractor angle (PA) plus 90°. You can repeat your measurements for accuracy. Do ask for help if you are unsure.

“What is the declination of the wall for a sundial?” A stone sculptor asked us just this question recently . It is a good question because you must know the declination if you are making a sundial that is accurate for the wall. The sculptor was not confident about their own measurements and calculations so they asked us for help. Continue reading

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New design of armillary sphere takes shape in Edinburgh

New design of armillary sphere taking shape

A new design of armillary sphere takes shape in Edinburgh, inspired by an original sundial from Northern Italy. The skilled blacksmith work is complete. This is a bespoke design with gold highlights still to be painted.

A new design of armillary sphere has been taking shape in Edinburgh. It is inspired by an original sundial from Northern Italy which has an attractive and distinctive form. The expert blacksmiths at Ratho Byres Forge have done an excellent job in working from our design. Continue reading

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New Sundial for Lews Castle at Stornoway, Isle of Lewis

New sundial for the cast iron pedestal found at Lews Castle, Stornoway

The new sundial explains the history of Lews Castle. It will be installed in the sunken garden as part of a regeneration project.

Lews Castle at Stornoway on the Isle of Lewis in the Western Isles is in the far north of Scotland. It once belonged to the wealthy overseas trader Sir James Matheson, who built the castle as a mansion home on the site of the ancient Seaforth Lodge in the 1840s. He planted woodlands to surround his property and laid out pleasure gardens with species imported from all over the world. An extensive programme of work to regenerate the castle grounds began in 2019. When an original cast iron pedestal was discovered at the castle it was decided it should be restored. It now has a new sundial, which is just finished, and Continue reading

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Time lapse study of shadows and how a sundial reads the time

Time lapse on precision of a sundial

Time lapse camera set up for study of a sundial looking at precision of the time shadow

There are many interpretations of how well a sundial reads the time. It is often thought the smallest increment of time on a sundial will be around two minutes. This is because the large diameter of the sun gives a fuzzy edge to the time shadow. Our study looked at the shadow Continue reading

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Restoration of the obelisk sundial at Drummond Castle gardens

THE DRUMMOND CASTLE OBELISK SUNDIAL

The sundial consists of 61 multiple dials on raised panels and in sunken hollows. The date of the sundial is 1630. It has been made as an exhibition piece to show all of the sundial mathematics of its era.

The sundial obelisk at Drummond Castle in Perthshire has a long and distinguished history. It has its place in the architecture of the ancient castles and houses in Scotland. It is connected with the very earliest days of the British Sundial Society (BSS). And it is one of the most important free-standing sundials in the British Isles from the early 1600s still surviving.

In 2017 after almost four hundred years outdoors the sundial was showing serious signs of the stone deteriorating. The whole structure was feared to be unsound. Making it safe had become urgent. Continue reading

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