<http://schema.org/description>
"Babbage&amp;amp;#39;s &amp;amp;#39;Difference Engine&amp;amp;#39; - he was continually modifying the design, as with modern computers, so it is not possible to date this precisely"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mediastorehouse.com/babbages-engine-1/print/594310.html>