A sky lantern also known as Kongming lantern or Chinese lantern or Fanush, is a small hot air balloon made of paper, with an opening at the bottom where a small fire is suspended.
Fanush (ফানুস, also spelt as Phanush or Fanus), paper made hot air balloon, was once the integral part of North Calcutta (Kolkata) “Babu” Culture. Today the art of Fanush making is a dying art as the new generation has shifted its attention to other sources of entertainment.
In Asia and elsewhere around the world, sky lanterns have been traditionally made for centuries, to be launched for play or as part of long-established festivities. The name "sky lantern" is a translation of the Chinese name but they have also been referred to as sky candles or fire balloons' or even 'lava blimps'.
The general design is a thin paper shell, which may be from about 30 cm to a couple of meters across, with an opening at the bottom. The opening is usually about 10 to 30 cm wide (even for the largest shells), and is surrounded by a stiff collar that serves to suspend the flame source and to keep it away from the walls.
When lit, the flame heats the air inside the lantern, thus lowering its density and causing the lantern to rise into the air. The sky lantern is only airborne for as long as the flame stays alight, after which the lantern sinks back to the ground.
