Mike Thank You....this is an excellent group of references you have so proficiently put together... Thank You... They are an amazing read..... As well as an encouragement to us modern day explorers.Pitlamp did: Post in thread 'Suggested photogenic walk-in entrances?' https://ukcaving.com/board/index.ph...hotogenic-walk-in-entrances.21902/post-278051
More from a family website: https://www.christopherlong.co.uk/gen/relationsgen/fg06/fg06_020.html
& also: http://www.expo.survex.com/jnl/1972/50yrs.htm
Cambridge Underground 1988: The Life and Work of C.F.D.Long
cucc.survex.com