400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Letter+illustrative+Gospel+history,+Epistles,+connected+it,+reply+mr.+Gibbon+[in+history+decline+fall+Roman+empire]+mr.+Faber,+others+nehemiah+nisbett because the request was invalid.

This might be because the link was created a long time ago. Try your search again on Google. That’s all we know.