Trivia: In the "Semaphore version of Wuthering Heights" sketch, much of the sempaphore is nearly correct. The first two subtitled lines are "Oh. Catherine" "Oh. Heathcliff" - what is actually signalled is "Oh Oh" "Oheath". The nurse signals "SS" and the sleeping man does signal "ZZ".
Trivia: The head of comedy at the BBC said that the title had to include the word "Circus", because the people at the BBC had referred to the six cast members wandering around the BBC offices as a circus, so added "Flying" to make it sound less like a real circus and more like something out of the first world war. And in front of that, added "Monty Python" because it sounded like a really bad theatrical agent, and also the large, constricting snake was also appropriate imagery.
Trivia: The 'Mouse Problem' sketch in Series 1, Show 2 (first broadcast 12/10/69) originally urged viewers who felt that they suffered from a similar affliction to phone an onscreen telephone number. This turned out to be David Frost's home number. This tale has been well documented in many places, with Frost devoting a page or two to the stream of irritating phone calls he received as a result in his autobiography. However, what is less well known is what happened next. Frost complained to the BBC and the Postmaster General, with the result that the episode was re-edited in August 1970 with new contact details and a fresh voiceover from Cleese. This was reportedly cut directly into the master tape of this episode, with the result that the original version no longer exists.
Trivia: The "Wacky Queen Victoria Sketch" which appears in the episode was, in fact, the first-ever Monty Python sketch to be recorded. It was recorded in the grounds of Ham House, Petersham, Surrey, from 9:30am on Tuesday July 8th 1969. (Source: Michael Palin's published diaries).