Sam's Sky Lanterns

g is usually about 10 centimetres (3.9 in) to 30 centimetres (12 in) 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. In Thailand sky lanterns are often traditionally made from oiled rice paper on a bamboo frame. They may also be constructed from other lightweight papers. The source of hot air is usually a small candle or fuel cell composed of a waxy combustible material lit and which usually stays lit despite the surrounding air currents. Many areas of Asia, however, do not permit sky lanterns because of widespread fire hazards, aviation risks as well as danger to livestock. In Brazil, Mexico, and possibly other Latin American countries, sky lanterns were traditionally made of several patches of thin translucent paper (locally called "silk paper"), in various bright colors, glued together to make a multicolored polyhedral shell. A design that was fairly common was two pyramids joined by the base (a bipyramid, such as the octahedron) sometimes with a cube or prism inserted in the middle. Only the smaller models had a full frame made of bamboo or thin wire; the slight overpressure of the hot air was sufficient to keep the larger ones inflated, and the frame was reduced to a wire loop around the bottom opening. The "candle" was usually a packet of paraffin or rosin tightly wrapped in cloth and bound with wire. 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.