The word "circus" comes from the Latin circus - "circular". Thus, the very name of this type of performing arts indicates the shape of a circle. The circus building, and the hall where the performance takes place, and the arena, which is its center, has this form.
The shape of the circle is directly related to the origin and history of circus art.
Circus history
The very first circuses appeared in ancient Rome. However, these were not circuses in the modern sense, gymnasts and acrobats did not perform there. In ancient Roman circuses, chariot races and horse races were held. In the modern world, the Greek word "hippodrome" is used to designate the place of such competitions.
The birth of the modern circus took place at the end of the 18th century in London, and it was also associated with equestrian sports. The creator of the new circus - the Englishman Philip Astley - was a rider, so the basis of the spectacles that he offered visitors to his establishment was precisely the demonstration of equestrian tricks, although such numbers were already supplemented by acrobatic sketches.
Later, Astley and his followers expanded the circus program to include performances by tightrope walkers, jugglers, clowns, and yet equestrian numbers remained the main theme of circus performances for about a hundred years. The structure of the circus arena was formed with a view to the performances of the riders.
Equestrian tricks in the circus
Horses should run smoothly and with regularity. This cannot be achieved if there are corners, so the arena should not have them, i.e. it should be round.
The convenience of the riders' performance was dictated not only by the shape of the circus arena, but also by its size. The diameter of the arena was established in 1807 at the Franconi Circus in Paris and has not changed since then. It remains the same now. The diameter of the arena in all circuses in the world, in whatever country they are located, is 13 meters (in the English system of measures - 42 feet). This diameter is determined by the laws of physics, on the basis of which horse tricks are built.
The centrifugal force acting on it depends on the diameter of the circle along which the horse runs. In turn, centrifugal force determines the angle at which the horse's body will be tilted in relation to the arena while running. It is with a diameter of 13 m that the angle is optimal for the rider who needs to maintain balance while standing on the horse's rump.
For illusionists, gymnasts, acrobats, clowns and other circus performers, the shape of the arena and its size are of no fundamental importance. However, for them, the invariability of the shape and size of the arena in all circuses of the world is also important. Thanks to this, the numbers staged in a particular circus do not have to be specially adapted during the tour.
