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.
Papyrus was likely first manufactured on a large scale early in the fourth millennium B.C., though the oldest surviving papyrus sample dates farther back, to around 4500 B.C. Though the papyrus sheets and scrolls were most commonly used as a writing surface, the ancient Egyptians had many uses for papyrus.It was used to make sandals, hats, mattresses, baskets, ropes, and other household necessities.As mentioned earlier, papyrus and its manufacture were highly prized in ancient Egypt, and soon after its development, the Egyptian state imposed a state-run monopoly on both the plant and the manufacturing process.t was used to make sandals, hats, mattresses, baskets, ropes, and other household necessities. As mentioned earlier, papyrus and its manufacture were highly prized in ancient Egypt, and soon after its development, the Egyptian state imposed a state-run monopoly on both the plant and the manufacturing process.