Among the different kinds of hanabi (fireworks) in Japan, the tezutsu hanabi is probably the one you really shouldn't try at home. "Tezutsu" means "hand-held," and a tezutsu hanabi cylindrical cartridge is made of a hollowed out bamboo tube, which is wrapped in rope woven from rice straw. The tube, which is usually around 80 cm tall and 15 cm wide, is packed with 1.5 to 3 kg of gunpowder. It's believed that the tezutsu hanabi evolved from the use of similar devices as signals in warfare 400 years ago. The tube is hand held when lit, and it can blast flames and sparks up to 10 meters high into the air.