Every Man a Gnomon

It's always good to discover a new word, even if its likely fate is to languish unused in some remote recess of the verbal mind until entirely forgotten. The other day, in the unlikely setting of Wellington's magnificent botanic gardens, I came across one that is surely destined for such a fate - 'analemmatic'.
 What you see pictured above is, it seems, an analemmatic sundial. And what is an analemmatic sundial? I refer you to Wikipedia, in the hope that you can make more sense of the description than I can. The root of the word is 'analemma', a kind of chart of the changing position of the sun in the sky through the year, as mapped from a particular point.
 Well, that's good to know. This particular sundial is labelled 'The Sundial of Human Involvement', which makes one fear the worse – some kind of PC representation of the dire effects of humanity on sweet Mother Earth? But no – what it is is simply a human sundial. You, the representative human being, stand at the appropriate point in the year, with your back to the sun, raise your arms above your head, and note where your shadow falls to discover the time. You are the gnomon – a word that has stuck, and has finally come in useful.