just found City of Laughter at the library--

"Or, to put it more simply, the fact that a George Cruikshank print from 1819 shows the Prince Regent farting at radical petitioners demonstrates that someone, somewhere, apart from Cruikshank, must have thought the image sufficiently meaningful to have parted with cash for it. Even if only one punter bought it - unlikely, since the most popular of these prints sold in their hundreds - the image stands as a flag for what was still 'thinkable and doable' during that dark, difficult year of 1819, when scores of working men and women protesting against the government's increasingly jittery attitude to democratic freedom were mown down at Peterloo."