A Ruben’s tube, also known as a standing wave flame tube, or simply flame tube, is a physics apparatus for demonstrating acoustic standing waves in a tube. Invented by German physicist Heinrich Rubens in 1905, it graphically shows the relationship between sound waves and sound pressure, as a primitive oscilloscope. Like history? Follow us @historyphotographed ❤️ | History In Pictures

267K views · 5.6K reactions | This woman don light fire inside flame  Party. CPDM Militant Hadja Haoua Aboubakar who is highly wanted and restricted from leaving Cameroon has released another audio in which she claims that President Paul Biya's candidacy did not come from him but rather Minister Ferdinand Ngoh Ngoh who wants to use it as a means to continue ruling Cameroon. Sey make Cameroon soldiers no leave Mr Ferdinand Ngoh Ngoh for continue. | Bafut Pikin TV | Facebook