Crikey its tomorrow already! ;)

Partial lunar eclipses come and go but Total lunar eclipses come in clusters every 4 years.
The next lunar total is visible in march 2007.
During the last cluster I only got to see one of the four because of bad weather (but thats another neolithic weather/climate thread for another time)

The 47 years thing is that is the cycle it will take for the partial eclipse moon rise to appear in exactly the same place.
I think anyone over 25 could have witnessed a pattern in lunar eclipse types that could have been refined over two or three generation.
I know of three ways of predicting eclipses using the Aubrey holes (2) and the inner horseshoe shaped setting of 19 bluestones (1).

A shame the solar eclipse (ring of fire) was not visible here on friday.
http://www.spaceweather.com/eclipses/22sep06/Schoppmeyer1.jpg
PeteG