I'm sorry. I sent my last message while I was still composing it, hence the two paragraphs after my signature that I hadn't intended to send.
I now realise, after re-reading Heiner's email, that I had mistakenly thought he was spinning the globe so as to make the same side face the sun. In fact, he's spinning it the opposite way. So, relative to the stars it will spin not 366.25-365.25 times, but 366.25+365.25 times a year. So I am even more baffled than I was before. Or even more mistaken. By the way, rather than using an anticlockwise 24-hour movement at the globe's south pole, you could use a clockwise 24-hour movement at the north pole. I recently bought a 24 hour quartz movement for a heliostat project. It took months to arrrive, cost £35 and is of no better quality than the 12 hour movements sold for £1.99 by Argos as alarm clocks. So, I'm now converting a £1.99 movement by butchering one of its wheels. Actually, I've made it go at a quarter speed, so it becomes a 48 hour movement. After aligning its axis with the poles, a mirror attached to the hour hand then reflects a spot of light in the same direction all day long. Over a year it traces a figure-of-eight on a wall. Regards Chris Lusby Taylor 51.4N, 1.3W -
