“JMW Turner was one of the most egotistical of all the 19th-century artists, with a firm belief that he was a match for any of his contemporaries – or indeed any painter who had gone before him. Now that lofty self-assessment is to be put to the test on an unprecedented scale. The Tate announced today that for its big autumn show this year it would hang Turner’s responses to some of the greatest paintings side by side with the originals.”