Per Wikipedia:
The trampoline-like life nets once used by firefighters to catch people jumping out of burning buildings were invented in 1887.
Circus Royal refers to performance on trampoline. The device is thought to have been more like a springboard than the fabric-and-coiled-springs apparatus presently in use.
These may not be the true antecedents of the modern sport of trampolining, but indicate that the concept of bouncing off a fabric surface has been around for some time. In the early years of the 20th century, some acrobats used a “bouncing bed” on the stage to amuse audiences. The bouncing bed was, a form of small trampoline covered by bedclothes, on which acrobats performed mostly comedy routines.
According to circus folklore, the trampoline was supposedly first developed, with the possibility of using the trapeze safety net as a form of propulsion and landing device and experimented with different systems of suspension, eventually reducing the net to a practical size for separate performance. While trampoline-like devices were used for shows and in the circus, the story of Trampolin is almost certainly apocryphal. No documentary evidence has been found to support it.
First modern trampolines
The first modern trampoline was built by George Nissen and Larry Griswold in 1936.[2] Nissen was a gymnastics and diving competitor and Griswold was a tumbler on the gymnastics team, both at the University of Iowa, United States. They had observed trapeze artists using a tight net to add entertainment value to their performance and experimented by stretching a piece of canvas, in which they had inserted grommets along each side, to an angle iron frame by means of coiled springs. It was initially used to train tumblers but soon became popular in its own right. Nissen explained that the name came from the Spanish trampolín, meaning a diving board. Nissen had heard the word on a demonstration tour in Mexico in the late 1930s and decided to use an anglicized form as the trademark for the apparatus.[3]
In 1942, Griswold and Nissen created the Griswold-Nissen Trampoline & Tumbling Company, and began making trampolines commercially in Cedar Rapids, Iowa.
The generic term for the trademarked trampoline was a rebound tumbler[4] and the sport began as rebound tumbling. It has since lost its trademark and has become a generic trademark.
Early in their development Nissen anticipated trampolines being used in a number of recreational areas, including those involving more than one participant on the same trampoline. One such game was Spaceball—a game of two teams of two on a single trampoline with specially constructed end “walls” and a middle “wall” through which a ball could be propelled to hit a target on the other side’s end wall.[5]