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.
The use of papyrus as a writing material was not limited solely to Egypt. Papyrus was exported throughout the entire ancient Mediterranean world. The introduction of paper in the ninth century CE signaled the beginning of the end for papyrus as the most important writing material of the ancient world.heir roots were a source of food, medicine, and perfume. Their stems were used to make baskets, floor mats, ropes, clothing, footwear, boats, assorted building materials, and the most important writing material in the ancient world. The use of papyrus in making writing materials dates back to Predynastic times.