In praise of sundials

WITH the nights drawing in as we head deeper into autumn, it may surprise you to learn that, for the past few weeks, my attention has not been devoted to the night sky. Instead, my free time has been entirely focused on the sun. That’s because this year, my autumn project has been to construct and set up an accurate sundial in my Portobello garden.

I am a huge fan of sundials; in my opinion the more sundials proliferate the better a place is to live. In an age when we all carry hyperaccurate digital timepieces, there’s something enormously satisfying about being able to tell the time using a piece of public art and the sun’s shadow. If I had my way, there would be sundials in all public places (this is why I’d never make a good mayor!)

My favourite Dunedin sundial is on a rather ornate base at the Botanic Garden. It was after wandering past this splendid celestial timepiece during a particularly sunny lunch break earlier this year, I decided it was time that my own back garden was graced by a solar clock.

There are many types of sundial; they can be horizontal (like the one at the Botanic Garden) or vertical (positioned on the walls of a building). I especially love more ornate variations of basic sundial design, such as the armillary sphere, which is an intricate array of precisely aligned rings.

In practice, my limited budget and Mrs Griffin’s lack of enthusiasm for what she described as a potential eyesore (did I mention I was personally designing this masterpiece?), meant that I had to limit myself to creating a standard horizontal sundial.

I am sure readers will be interested to learn that the key element of any horizontal sundial is the gnomon, which casts the shadow. This has to be precisely crafted to match the latitude of your observing site, and accurately aligned to point south.

After some effort, my garden sundial (cast from aluminium) enjoyed its ‘‘first shadow’’ last month, and despite recent cloudy weather, I am absolutely delighted with my new garden feature.