Every issue of New Scientist from 1956 to 1989
books.google.com
books.google.com
Google blog entry when they introduced the feature: http://googleblog.blogspot.co.uk/2008/12/search-and-find-mag...
(and old partial list with links: http://duvet-dayz.com/archives/2008/12/11/1037/ )
the full list of English magazines on Google Books: http://books.google.co.uk/books/magazines/language/en
If it shows up I'd highly recommend looking at it, specifically for the editorial setting out the frame of reference for what the editors intended the magazine to do: it had a mass-educational brief that is virtually absent from science and tech reporting today. (Instead we get lots of gosh-wow sense-of-wonder stuff but precious little substance or analytical thinking.)