Dear Paul et al, > Too bad there wasn't any sunshine > for the unveiling, as I see no > hint whatsoever of a shadow.
It was a typical U.K. wet afternoon! You can see another pic at: http://www.cambridge-news.co.uk/Cambridge/Human-sundial-unveiled-on-Jesus-Green -commemorates-Cambridge-sculptor-Vernon-McElroy-20140512145351.htm If you click on the picture it gets bigger! I am definitely better dressed than the Mayor or the Lord Lieutenant :-) This makes it very clear that the sundial is supposed to be a Douglas Hunt design but it hasn't been implemented properly. Douglas kindly telephoned me and pointed out many subtle errors that I hadn't taken in. He didn't seem too troubled by a newspaper using his logo without proper accreditation. He was much more put out that whoever laid the dial out didn't do it properly. Quite right! Neither he nor I have any idea how his design somehow arrived here in Cambridge. I shall see some of the sponsors on Thursday but those I saw last week had no idea who managed the project. For those unfamiliar with the Douglas Hunt scheme, here is an outline: For a given place, design TWO analematic sundials, one with a major axis of 4.5m and one with a major axis of 6m. Place the two on top of each other so the two pairs of axes coincide. On the date line, remove the northern half from the larger design and the southern half from the smaller design. [The result is an asymmetric date line: winter to equinox is longer than equinox to summer.] Leave the two sets of hour points but have the outer ring showing winter hours and the inner ring showing summer time hours. This way you get a single date line but its scale changes in the middle. The neat point is that shadows are shorter in summer so you use the smaller ring of numbers. As a refinement, you deem summer to start on 1 April and end on 31 October. Strictly you should then get a gap between 31 October and 1 November when you switch scales. It would be a good student exercise to explain this gap! This arrangement more or less coincides with the dates of summer and winter time in Europe. It is a pity whoever did it didn't consult Douglas! As it is, we have all the bits but incorrectly laid out! Frank King Cambridge, U.K. --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
