Popular Science is partnering with Google to make their entire 137 year archive available for free browsing.

story: http://www.popsci.com/announcements/article/2010-03/new-browse-137-years-popsci-archive-free
archive: http://www.popsci.com/archives

Is that archive new though? I actually integrated the full view Popular Science from Google Book search quite some time ago at Cover Browser:
http://www.coverbrowser.com/covers/popular-science

(For some reason I can't open the full view right now, but that used to work.)