Queensland State Archives posted a photo:
History of Butterfly Chair
Known by many aliases, including the sling chair and the Nap chair, the butterfly chair has been quite popular since it was created and perceived as an easy-going lounger. Historically, the butterfly chairs have origin since the 19th century and were used as military furniture.
They were first created in 1938 (just after World War II), through an Argentinian architectural firm called Grupo Austral, and were an updated design of the Paragon Chair. In the 1870s, this chair was very popular in the US as campaign furniture and was specifically made for travel.
The butterfly chair was the first piece of furniture to be made with tubular steel, but its wooden counterparts were manufactured since the 1850s. These folding ‘campaign’ wooden sling chairs were created for the British military by an English engineer named Joseph Fenby.
The butterfly chairs available in the modern era