Sign of the Time

Handcrafted sundials are elegant and surprisingly accurate

Capel Tenison of Border Sundials in Wales produces engraved horizontal plates in brass for £120. A professional dialmaker skilled in both the calculations and the crafts involved, he marks the hours on every plate and positions each gnomon (the indicator that casts the shadow across the dial) according to the specific latitude and longitude of the client's garden, thus ensuring accuracy.

For although we use Greenwich Mean Time (and British Summer Time), the sun's position varies depending on how far east or west of the Greenwich meridian you live. For example, Bristol was happy operating about 10 minutes behind London until the country moved to GMT in 1880, as a consequence of the expansion of the railways.

"The maths behind it might sound complex, but some of the principles are really quite simple," says Tenison. "The angle of the gnomon always has to run parallel to the axis of the earth, for instance."

Sunday Times, Home Section, Katrina Burroughs, 9 September 2007