In article , Sue Begg
writes
In message , Janet Tweedy
writes

Why doesn't anyone invent a spirit level that's really a flat square
with the bubble bit in the centre and four radial glassy bits so you
can see each way at once if you balance the flat square on top of things


We had one for the caravan that would give you the level front to back
and side to side at the same time

I must look for one then, I knew there ought to be something like that
but the only device I've ever known was an anti trembling device on
bombs which is filled with a mercury 'bubble' instead of an air bubble
and then any movement would make a contact.
--
Janet Tweedy
Dalmatian Telegraph
http://www.lancedal.demon.co.uk