On 19/03/2018 10:26, Brian Gaff wrote:
Well the earth is curved after all, so in reality nothing is flat or level
is it?

Nothing's flat or level in this house. It probably wasn't when it was
new (peasant's cottage) and now one of the upstairs floors has a 1 in 10
slope!

On the walls - I don't try to make things level. I make them parallel to
the floor or ceiling (if close) or half way between. On the walls with
exposed vertical timbers pictures are hung to line up with the timbers.

Andy