Those are Avro Lancasters - in this case Canadian built. The Short Stirling was larger still, although not in wingspan, while the Halifax was a similar size to the Lancaster. Most W.W.II four-engine heavies were actually relatively similar in size, only the B-29 and B-32 (being a further generation on) were significantly larger.
Size comparison of the three RAF heavies here:
http://en.wikipedia.org/wiki/File:Briti ... arison.pngI'm delighted to see Mark's recent threads have been introducing people to previously unfamiliar aircraft. There's a whole world of interesting aviation out there.
Regards,