Constable 's watercolours were also remarkably free for their time : the almost mystical `` Stonehenge '' , 1835 , with its double rainbow , is often considered to be one of the greatest watercolours ever painted .
Constable 's watercolours were also remarkably free for their time . The almost mystical `` Stonehenge '' , 1835 , with its double rainbow , is often considered to be one of the greatest watercolours ever painted .