People often ask what is so special about the Spot-on Sundial and how it came to be designed. If you too are interested in this, here is the full story.
I have been interested in sundials for 25 years or more, ever since I attempted to make a sundial from a vertical post stuck in the ground and found it didn't work. Later, when I found out why it didn't work from a book in the library, I started making painted wooden sundials.
A few years later, a friend suggested I should join the British Sundial Society, and at the following annual general meeting, I made a suggestion for organising a periodic awards scheme. At the end of that meeting, I was invited to join the council with responsibility for setting up the scheme.
In 1996, I had become very interested in the Internet, and suggested that the British Sundial Society should set up an information site about sundials. At that stage in the development of the Internet, it was not at all clear how much money a website would cost and what benefits it would bring, so the idea fell on stony ground. So I decided to set up www.sundials.co.uk on my own account, and it has subsequently become the leading world internet site on sundials.
For many years, I and others in the world of sundials, have been concerned with one major problem - "Why are garden sundials so awful, and what on earth can be done to improve them?" Why they are so awful is fairly easy to answer - it is very easy to make something which looks like a sundial and to sell it as a garden ornament to people who are not really interested in whether it works as a sundial. (Such sundials can now be imported by the container load from the Far East at a price of £3 each. These objects should not really be dignified with the name of sundials, because they are not capable of telling the time from the sun. (In addition, many of them are badly made, and very few come with any instructions on how to set them up).
In the year 1999, my wife very kindly took me on a bus tour of Guatemala, and, in between seeing the extensive Maya ruins and enjoying the spectacular scenery and friendly people, we had a certain amount of time waiting around for buses. Deprived of both computer and workshop, I started thinking about the garden sundial problem, and came up with an idea - a split gnomon would remove the difficulties in setting up a horizontal sundial, and, if it was well made and had good instructions with it, it could also be very accurate. Also, I thought, it would provide a good opportunity to branch away from the traditional designs, which are usually feeble echoes of seventeenth or eighteenth century dials, and to produce a clean modern design appropriate to the century we live in.
Thinking these ideas is the easy bit! The difficult part is putting them into practice. I very nearly gave up, because it seemed that they were going to be impossibly expensive to make, and would thus never get any orders. And then I had a stroke of luck - I met somebody who imported goods from India, and had an agent there, and he put me in touch with a company near Delhi who, after three prototypes, produced a high-quality product at a price which would make it possible to sell in European markets.
The rest is history - we have so far sold many Spot-on Sundials, to customers all over the world, and are continuing to grow year on year.
A few years later, we introduced a range of stainless steel sundials. These are made from 10 mm. stainless steel, so are virtually impossible to damage, and are thus suitable for public parks and other open locations. They are fixed to a plinth or other horizontal surface using concealed fixings bonded in with resin, which makes them extremely difficult to steal. And they have a great "wow factor" with the glint of the sun to advertise their presence at a distance, the stunning reflections in the mirror-polished surface to give fascinating reflections of the sky and the surroundings, and the "event" of the shaft of light shining through the slit in the gnomon at solar noon
Innovation has continued with the introduction of three new designs.
The first was the brass Polar Sundial (modelled on a large sundial I designed for the Millennium on the north bank of the Thames in central London,
Next came the development of a Universal Vertical Sundial, consisting of two hinged plates which could be set an any angle from about 10 to 70 degrees to compensate for the declination of the wall, and to ensure that the dialplate faced due south. This was quite a good idea, but it proved very expensive to manufacture, and was also very heavy, so we never put it into production.
Following this, I went back to an idea from some years before, to make an equatorial dial in which the dialplate had 24 spokes like a wheel. The idea had been developed in discussions with Sustrans, the cycle charity, but there was insufficient funding to proceed with it then. A successful prototype was produced, and it was then put into production as the Skywheel.
I had always wanted to have in the range a sundial suitable for equatorial latitudes. Horizontal dials do not work well in the Tropics (say between 30 deg. N and 30 deg. S) because the angle between the gnomon and the dialplate is small (being equal to the latitude) and this means that the hour lines are very close together, and thus difficult to read. There is, of course, a method of tilting a horizontal sundial designed for one latitude to work accurately in another, but it demands making a plinth or other support tilted in a north-south direction at an angle equal to the difference between the two latitudes, and is thus not widely used. My idea was to use a polar sundial mounted on a central spindled so that the gnomon could be titled to any angle between 0 for the Equator and around 70 deg for northern Norway/ This Universal Polar Dial can be set to the angle of the latitude of its first location, and then adjusted to the angle of the latitude of any other location (in the same hemisphere) which it may be moved to subsequently.