I'll bet you did not ask for a sundial pint beer glass for Christmas? The standard 23oz over-measure glass has an annular area where the sun shines through and casts a shadow on a complex transfer applied to the other side. You rotate the glass so that the shadow falls into the area marked with the month and read off the time. It seems to work for five hours either side of midday - if you can find a pub open at seven in the morning! The level of beer has to be below the cast shadow otherwise refraction through the liquid would come into the equation. The only other drawback is it is calibrated for Brighton (51 degrees north) but does work well in Dresden, Kazakhstan, north Mongolia and Calgary. The glass costs £15 plus p&p. Email: jackie@waitrose.com for more information.
