It's fairly easy to play table-tennis with square bats and an invisible ball but much more difficult if the ball is square and the bats are invisible!
Tony Hart, Pat Keysell
[and] Sylveste McCoy and Wilf Lunn
With The Prof
(The address to send paintings to Is: Vision On, [address removed]. We are sorry we cannot return any, but we do give a prize for each one shown.)