 The earliest known audio tape recorder was a non-magnetic, non-electric version invented by Alexander Graham Bell's Volta Laboratory and patented in 1886 ().It employed a strip of wax-covered paper that was coated by dipping it in a solution of beeswax and paraffin and then had one side scraped clean, with the other side allowed to harden.The machine was of sturdy wood and metal construction, and hand-powered by means of a knob fastened to the flywheel.