130 Days of Pseudopolis
Mentioned in Pyramids, this book is similar to The Shuttered Palace, except that, according to Ptraci, it includes physically impossible positions.
Annotation
The Roundworld referent is most probably the Marquis de Sade's 120 Days of Sodom, in which the positions are not completely physically impossible, but would involve a great deal of physical discomfort at the very least, and excruciating physical pain at the very worst. De Sade builds his unique personal philosophy in which he defines a basic human right to do anything he damn well likes to anyone he damn well chooses - allowing them only the right to become a sadist to others in their own turn (should they survive). As the book defines a sort of Fascist philosophy of human sexuality, this was filmed by Pasolini as a satire on the last days of Mussolini's Italy.