The Lamberts of Croydon One hundred and sixty years ago, two boys and a small girl riding on a donkey were painted by the famous artist John Constable. 'They are very well-behaved and amiable children, and the donkey is a fine, rough, good-natured animal' he wrote to his wife. Today may be your last chance to see this painting - when this great family treasure is auctioned at Sotheby's next week, it could well leave the country forever.