Dear FOG ( Friends of Gloria ),

For those of us who are fortunate enough to have a south-facing windowsill, there is nothing so soothing as to have the home comfort of an indoor sundial.To know the time at a moment's glance or just the focal point for some quiet contemplation.

But as anyone who has spent a little time with sundials will know, the reason they are scarcely used is that they tell the sun's time which is different from the clocks. The clocks beat equal ticks and tocks all year.

Believe it or not, the sun varies in the sky through the year between passing us quarter of an hour early in October/November and quarter of an hour late in February according to the clocks!

And because outdoor sundials are made fixtures to withstand the weather, every fixed sundial is subject to this time error. Every one!

Furthermore, partly because the earth's relationship with the sun is an ellipse, this difference isn't a simple curve; it has a double hump.

Firstly the Central (gnomon) Rod is pointed at the North Pole star, to be parallel to the earth's axis. That's standard practice.

The time scale is placed around it, giving known, equal scale divisions, housed in an open box which allows for the sun's rise and fall through the year. Graduations are every 5 minutes.

The box can be moved around the gnomon by up to +/- 4 degrees (about quarter of an hour either way) using an arm in order to follow the elliptical graph which is provided alongside, and there you are.

Furthermore the box can sit in a choice of two notches, black or red, 15 degrees apart, which shifts the scale by an hour to read either Greenwich Mean Time or British Summer Time.

A convenient sundial which can be kept accurate to clock time within a couple of minutes, summer or winter.

What more could you wish?   With much love, from Gloria.