Tom HolzelTom Holzel graduated in Economics at Dartmouth College, New Hampshire. In 1986 he organised and took part in an expedition to the north side of Mount Everest to search for new evidence of what became of Mallory and Irvine. He has invented and patente a new kind of oxygen 'rebreathing' apparatus for extended use at high altitude. He is the author on numerous articles for Summit, Mountain and American Alpine Journal. He is co-author, with Audrey Salkeld, of The Mystery of Mallory and Irvine. Read More Read Less