These vintage images are some fascinating, trivial ones that just explore one of the experiments of inventor Alexander Graham Bell in his collaboration with aeronautics pioneer Lawrence Hargrave. To put simply, an experiment on building a kite sturdy enough to carry both man and machine.
A tetrahedral kite is a multi-celled, rigid box kite, made with tetrahedrally-shaped cells to create a truss. Along with Hargrave, Graham Bell was an early invention on the road to manned flight, having worked with these between 1985 to 1910.
Unfortunately, this collaboration was not sufficiently appreciated during the time, despite Hargave offering the kite models to the state of New South Wales, Australia. Due to the delays of accepting the models, the two then gave the models to German professors who handed them to the Munich museum.
The most known models were the Cygnet I, II, and III (they were named after the young swan as they took flight on water).
Images are from the public domain.