Lecture notes, argh.
It's a plumb line, you South African nutter, a plumb line not a plumb bob.
'It's exactly not at all obvious.' WANKER.
In lieu of revision, I have been reading mock_the_stupid. Who knew that LJ breaks when you try to go past "/?skip=380"? (Argh. Too many question marks.) Many things on MTS are scaring me, but particularly this, and associated comments. Um. Wow.