Way back in 1992 - twenty five years ago as this page is written - a memorial was commissioned in memory of Dr Andrew Somerville - the first Chairman of the British Sundial Society. The Society  had been established only a few years previously in 1989. His untimely death was mourned by many and Christopher St JH Daniel, one of the founder members of the society was asked to develop a suitable memorial. The Bollington Arts Centre near Macclesfield in Cheshire hosted the formal inauguration in September 1992 and the Centre's magazine duly reported the event.  Do try and visit this unique monument when you might next be near Bollington, in Cheshire.




Saturday  September 26,  1992  8 pm


The work on the approach to the Arts Centre and the construction of the car park has involved quarrying a large amount of stone from the hill alongside the building. This has been accomplished by teams of workers on Sunday mornings doing community service. The work has been supervised by Edward Heath who has designed and planned much of it himself as well as working in his own time.
The untimely death of Andrew Somerville, who was a great supporter of the Bollington Arts Centre since its inception, prompted some of his friends to commission a sundial in his memory and this has now been erected at the top of the hill in a sort of ‘turret’ which is a most attractive place to sit out on a summer evening. Andrew was an expert on sundials and wrote the definitive work on Scottish sundials, so the memorial is very apposite.
His widow Ann will be giving a short talk about sundials during the evening. Elsewhere in this issue there is a short article on sundials by Chris Daniel who designed the one at the Arts Centre. It was carved by Mark Frith in Welsh granite which makes an effective contrast to the local sandstone of the walls.




A NOTE ON SUNDIALS [Text as written for the Bollington ArtsCentre Magazine, Autumn 1992]


The sundial, as a means of determining the time and regulating the clock, has faded into history and is regarded by most people as little more than a garden ornament or, at best, a rather second-rate ' solar ' clock. In fact, unlike a clock, the sundial is not a time-keeper as such, but an astronomical instrument the purpose of which is to determine the time by the apparent motion of the sun. It indicates the true time by the sun, which is called local apparent ( solar) time, which, when corrected for the difference in longitude of the place in which the sundial is situated from the standard meridian, will give standard apparent (solar) time. When corrected for the equation of time, ie. the correction for the earth’s varying orbital speed and the tilt of the earth's axis to the plane of its orbit, the sundial will give standard mean (solar) time. i.e. Greenwich Mean Time or everyday 'clock' time in the UK. The 'longitude' correction is a permanent correction and may be included in the construction of the sundial. The equation of time correction is variable and must usually be applied according to the date in question.


Basically, there are four primary classes of sundial:


Of these four classes, the equinoctial dial is the principal sundial, since it is fundamental to the whole science and art of sundial construction. The horizontal dial is the most common, of course, and the one of which most people think when the sundial is brought to mind. The vertical dial, on the other hand, is the sundial which flourished for centuries as the primary means of regulating the public clock, and many such dials are still to be found on historic buildings throughout the country. The polar dial, however, is the one

class of sundial that is comparatively rare, except in the form of a direct east-facing or west-facing vertical dial, or as a component of the cruciform sundial, usually to be seen on a plinth as a memorial 'cross'. Thus the direct 'south- facing' polar sundial, in which the plane of the dial 'reclines' from the vertical, at an angle complementary to the angle of the latitude of the place for which the dial has been made, is something of a rarity.


The sundial at the Bollington Arts Centre is just such a rarity, indeed its design makes it unique. The shape of the sundial brings to mind the Scottish ' lectern' dial, which is a class of multiple sundial to be found in Scotland, on which Dr Andrew Somerville was the leading authority in recent years.


(1) the horizontal sundial, in which the plane of the dial-plate lies in the horizontal plane;

(2) the vertical sundial, in which the plane of the dial-plate or dial-face lies in the vertical plane;

(3) the polar sundial, in which the plane of the dial-face lies parallel to the plane of the polar-axis of the earth; and

(4) the equinoctial sundial, in which the plane of the dial-plate lies in the plane of, or parallel to the plane of the equinoctial, ie. the equator, or in which the hour-lines of such a plane are extended to the encompassing cylindrical or spherical surface, in order

to facilitate the use of the instrument.


Most people, perhaps, may remember Andrew Somerville for his interest and expertise in sundials. He is revered as the first chairman of the British Sundial Society, of which he was the principal founding member when the society was formed in 1989 .

But Andrew had many interests and many talents, one of which was a great love of music. He was a founder member and enthusiast for the Bollington Arts Centre, Chairman of the Bollington Chamber Music Group, and member of the Bollington Festival Choir. The sundial in his memory has been cut from a rectangular block of blue pennant stone, the dial face lying at an angle of 37 degrees to the vertical. On the south face is carved the inscription 'In memory of Andrew Somerville 1923-1990'.


Christopher St J H Daniel


NB.  Christopher Daniel MBE designed the memorial polar sundial at the Arts Centre and SunInfo is grateful for his permission to publish this short article.