Venter Borass is a wizard, now buried in the private cemetary of Unseen University. Possibly he hasn't noticed. He spent his whole life down at the bottom of some hole or other. Borass is famous for putting forth the theory that the fossilized magical fields in long-buried rocks showed the occasional reversal of the Discworld's direction of spin. He is also known for several other theories about what is essentially Discworld geology; that rocks found deeper underground are likely to be older than rocks on top (instead of being arranged by colour, as was the commonly held theory at the time), that mountains gradually turn into grains of sand (instead of the other way round, as dictated by common sense), and that the continents of the Disc were all formerly one landmass, which he named Pango