THE ANGLE OF DANGLE
This little gizmo arrived in the post this morning. It's a magnetic, electronic angle finder thing. It's really useful for quickly checking the head angle of bikes, office cabinets, desks and cups of tea.
It has a zero function so you can set whatever surface you have as the datum, then take a reading off that. I now know that the walls in the office aren't vertical and that the floor is sloped, that probably explains quite a lot.