pp 190-2 of Proceedings of 2nd International Cryogenic Engineering Conference, Brighton, Eng., 7--10 May 1968. Guildford, Eng., Iliffe Science and Technology Publications Ltd., 1968.; Other Information: See CONF-680505. Orig. Receipt Date: 31-DEC-69; Bib. Info. Source: UK (United Kingdom (sent to DOE from))