Astley did not invent trick-riding, which was already a popular entertainment of the period. Nor did he originate the idea of performing in a circular 'ring'. The use of the circular arena is successful for two reasons. First, it is easier for the audience to keep the riders in sight. Second, the circular ring (though Astley called it 'the Ride') helps riders through the generation of centrifugal force, which assists them in keeping their balance while standing on the backs of their galloping horses. Astley never called his 'Astley's Amphitheatre of Equestrian Arts' a "circus"; that title was thought up by Charles Dibdin, who in partnership with Astley's rival Charles Hughes, opened the "Royal Circus" on 4 November 1782, a short distance from Astley's in Lambeth, London. After a few years, Astley added a platform, seats, and a roof to his ring. Even after his death Astley's "Royal Amphitheatre" remained famous throughout the nineteenth century, being mentioned by Charles Dickens and Jane Austen. It was closed in 1893 and was demolished the next year. The garden of St Thomas's Hospital now occupies the site; a commemorative paving stone (see below) marks the Amphitheatre's former position.