Do you have permission to waltz?

I love doing the research for my novels because sometimes I run across gems like this:

"The degree of commitment to Jacobitism has indeed become the Loch Ness Monster of eighteenth-century history.  The true believers are convinced not only that it existed but that it was huge...they relate the equivalent of alleged sightings, out-of-focus photographs and sonic soundings." 

 From A Conscise History of Britain 1707-1975 by W.A. Speck