-----Original Message----- From: dave dameron <ddameron(a)earthlink.net> Yes, I've got it here (bought as part of a $3 per bag haul from a charity book sale a month ago). You are right about year and publisher, but the "author" was Bolt, not Holt - it is part of a series called School Mathematics Project Handbooks and A.B Bolt actually lists himself as "supervisor" of 6 Exeter School 6th form boys who actually wrote the book. It describes a binary adder, a NIM machine, a noughts and crosses machine .... I see a few other replies, so that it is not all that rare :( - but what exactly did you want to know for? Phil Guerney Brisbane, Australia