On depressing a lever the propellant gas forced the flammable oil into and through a rubber tube and over a simple igniting wick device in a steel nozzle.
[2] Fiedler originally performed a trick called "Brennender See" (Burning Lake) at festivals in Berlin-Weißensee.
In 1905, he presented his flamethrower to the Preußisches Ingenieurs-Komitee (Prussian engineering committee) at the Garde-Pionier-Bataillon in Berlin and received suggestions for improving the device.
Independently of Fiedler, Bernhard Reddemann (1870–1938) had also begun developing flamethrowers, prompted by reports of kerosene pumps that the Japanese had used against bunkers in the siege of Port Arthur.
Fiedler and Reddemann met for the first time in 1908 and cooperated at the onset of the First World War on further developing the flamethrower.