Why does a query in rails with a limit not work unless .all is put on the end

I have a query like this:

locations = Location.order('id ASC').limit(10)

which returns an array of 500 or so records - all the records in the table - i.e. the limit clause is being ignored.

Yet if I put a .all on the end:

locations = Location.order('id ASC').limit(10).all

it works and returns 10 records.

This code is being run in a rake task and I am using PostgreSQL if that makes any difference.

Why is it doing that? Surely the .all should not be required. What am I missing?