Inner-tubes are the inflatable parts between the tire and the metal parts of the wheel. They are invisible apart from their valves that protrude through the wheel-rims. There are three valve types in use; Schrader valves, Presta valves, and the lesser used Dunlop valves. Refer to the adjacent image for examples.
The word papyrus /pÉËpaÉªrÉs/ refers to a thick paper-like material made from the pith of the papyrus plant, Cyperus papyrus. Papyrus can also refer to a document written on sheets of papyrus joined together side by side and rolled up into a scroll, an early form of a book.The plural for such documents is papyri.apyrus is made from the stem of the papyrus plant, Cyperus papyrus. The outer rind is first removed, and the sticky fibrous inner pith is cut lengthwise into thin strips of about 40 cm (16 in) long.
1 Egyptians used papyrus for 4000 years until other plants and trees were used to make paper for economical reasons. 2  Papyrus is still made, but normally only as a tourist attraction.