We're in the process of clearing out accumulated tqt from Dad's house. A Chartered Mechanical Engineer, his early working life was in a drawing office in Sheffield.
Consequently we've turned up misc. boxes of drawing instruments, a slide rule or two and various micrometers. The piece de wossname, however a box containing a gadget for drawing ellipses. It's got a perspex base plate and a swivelly arm with holes for poking a pencil though. He paid thirty seven and six for it.
Tis a thing of wonder, but will only gather dust.