 The subject was a sword-swallower, who swallowed a metal tube with a length of 47 centimeters and a diameter of 13 millimeters.On 2 October 1877, Berlin urologist Maximilian Carl-Friedrich Nitze (1848–1906) and Viennese instrument maker Josef Leiter (1830–1892) introduced the first practical cystourethroscope with an electric light source.The instrument's biggest drawback was the tungsten filament incandescent light bulb (invented by Alexander Lodygin, 1847–1923), which became very hot and required a complicated water cooling system.