You then spread open the wad of saturated spirit money and light in on fire. When the air inside of the lantern heats up, it grows lighter than the air around it and the lantern begins to rise. It's the same principle employed by hot air balloons.
施放時，將浸油的金紙散開、點燃，當天燈內的空氣受熱，密度比燈外空氣的密度小，天燈便會飛起來，與熱氣球的原理相同。