This ongoing project is just one part of an ambitious arts trail by Great Linford Parish Council

A large Gnomon (or shadow striker) is to be relocated, from it’s previous home in The Theatre District, to a site at the end of Millfield Gardens, Redhouse Park, Milton Keynes:

In this case the gnomon is a 5M long mild steel Circular Hollow Section, facing true South, at an angle of 52 degrees, making it parallel to The Earth’s Axis. As the planet rotates a shadow on the ground follows a clockwise path. The sketch below shows the hour lines from six AM to mid-day then up to six PM. The sketch below is of the site in plan, with the hour lines radiating out from the gnomon.

The length of the shadow shortens with the sun’s (relative) elevation, allowing us to mark the time of year in lines running across the radiating hour lines:

In this case six lines mark the twelve Signs of The Zodiac. Because the site is highly contoured, these lines distort, as the ground falls away from the line of the shadow. These lines could be picked out in slate off-cuts

Click here, or on above image for animation in new tab…

Here CAD has been used to simulate solar shadows. A survey of the site may be used to predict where shadows may fall at any time on any date of the year, allowing for the ground falling away from the shadow line.

The curved lines running across the site mark the zones through which the sun’s shadow will pass through various times of the year. These could coincide with the 12 signs of the zodiac, in special anti slip coloured coating, stenciled around the intersecting footpath. Below is a design depicting Aries the ram (March 21st to April 19th)

Here is a CAD Rendering of what the refurbished gnomnon might look like- in this case it has been extended with a laser- cut baffle, with four directional coloured glass filters, so that in bright sunlight the tip will change appearance with the sun’s position.

or in perspective:

A recent visit to Granlyn Specialist Coatings, agents for the Metalier finishing system, highlighted some interesting possibilities. Basically powdered metals (typically bronze or gunmetal) is applied in a substrate over an epoxy primer. These finishes can be chemically  patinated and/ or buffed to a reflective finish. The coating also has sufficient thickness to take a texture, either through stippling, or with a latex roller

Bronze Textured

Smokey bronze textured (Patinated, then buffed)

Rose Aluminium with applied texture.

 

Gunmetal textured

It will be appreciated that although the techniques shown are a fraction of the cost of a specialist foundry casting, they may prove to be beyond the budget of this project.

This is a more accurately scaled 3D CAD rendering of the current incarnation, modeled on survey data.

Again, this is a more recent version of the design. The softworks are as they were when this base photo was taken.

There will be some swathes of bulb planting at ground level- these will come out at different times of the year.

UPDATE: March 2022.

The design has evolved over time. Specified finishes have been altered, with a subtle polished patina to the gnomon and locally sourced ‘river cobbles’ around the base,

Here CAD renderings show the refurbished gnomon in position. This is currently being given it’s burnished gunmetal- like surface by Perfect Paints of Blakelands.

River cobble markers (Indicating both time and date) can be seen radiating outwards on the grass.

Draft artwork to an explanation panel, facing the gnomon. This shows shadow patterns across time & date, with their relationship to astrological symbols.

Unfortunately a delay between grit blasting & finishing allowed some rust to return, so some treatment on site was required, forcing me to do a lot of hand rubbing- down during the recent mini heatwave!

After handover to Milton Keynes Council, the markers needed mowing strips to allow a ride on mower. Initially sedum was considered but eventually a self binding gravel was considered less vulnerable to weeds.

Here ‘Epodex’ epoxy resin has been mixed with sand and gravel, before being applied between more vulnerable river cobbles, binding them securely to the concrete foundation below. More pea gravel is applied to give a more informal appearance & a dark jointing compound worked between the gaps to protect against frost damage. The black sheeting is a weed control barrier, awaiting some self binding gravel.

Fused glass sample segment by Vitreous Art of Towcester. This sample is a test piece- the final article will use tinted components, positioned at the gnomon’s tip, to catch the sunlight. Here you can see ‘seeds’ from the material, refracting sunlight passing through it.

The finished article in fused coloured glass.

Here is a 3D CAD model of an explanation panel stand in laser cut stainless steel. It is designed to be modular- here a ‘soundbox’ has been slotted into the front. Optionally up to three pairs of photovoltaic panels may be slotted into the South facing rear.

Area of bound gravel being dug out.

It was 12:00 BST on the 30th of July, 2024.

The shadow above was landing on the 11:00 GMT marker, this being 12:00 BST.
In late July, the shadow doesn’t stretch far from the gnomon, just passing the second line across the site, into a strip of ground donating the Leo star sign, as we are moving away from the Summer Solstice.
In the Autumn, with The Winter Solstice at our backs, the same strip delineates Taurus, The Summer Solstice nearing.

Close up of the lower ‘Test’ area of The Gnomon, now treated with a eggshell, transparent coating of Owatrol oil.

You are looking at fractal patterns of pitted rust, picked out in tanic acid rust converter, chemical blacking and a little splash of gold leaf.