James, here is an article on it.
[url="http://vads.ahds.ac.uk/diad/article.php?title=291&year=1973&article=d.291.27"]http://vads.ahds.ac.uk/diad/article.php?ti...rticle=d.291.27[/url]
[url="http://vads.ahds.ac.uk/diad/article.php?title=291&year=1973&article=d.291.27"]http://vads.ahds.ac.uk/diad/article.php?ti...rticle=d.291.27[/url]
![[Image: 26_8_1.gif]](http://i131.photobucket.com/albums/p303/pl8man/keepers/26_8_1.gif)