John Gunning developed his interest in sundials over many years whilst serving at home and abroad in the Royal Navy. His career allowed him, on occasion, to compare the theory with the examples which he encountered. Perhaps the most remarkable of these was the heliochronometer shown to him in an Army Officer's Mess in the Khyber Pass. His surprise at finding one there was only matched by the proud Mess Manager's amazement in finding, at last, someone who knew exactly what it was!

When embarking on a second career associated with the development and marketing of Lighthouses, John Gunning was again surprised when he discovered that, in this sphere too, sundials had been employed, right up to the beginning of this century, to check the clocks used to regulate the turning on and off of the light.

After making some early prototypes out of perspex, he made later models out of brass. A few of these he gave to friends and acquaintances and it was these fortunate recipients who urged him to consider marketing the device. The result is the present Heliochronometer, each one with its unique JPG serial number.

John Gunning, whose hobbies include ski-ing, sailing and golf, is married with two grown-up daughters and lives in Petersfield, Hants.

email gunsun@btinternet.com