You can find out the background to the project on the Townsweb Archiving blog.
I haven't really explored yet but the page scans look very good. My only comments are that you only see your results by Journal volume whereas a date would be nice, and to return to the search results you have to use the browser 'back' button: but that's being picky. It is a fantastic resource. Enter 'infra-red' and then 'infrared' as your search term and see how it all started.