Improvements on the wheel log The earliest wheels were disks cut from a log cleat Further improvement was made by sandwiching three disks with the wood grain crossing at angles of 60 degrees peg rim Wheels of larger diameter were made from three boards held together with cleats and wooden pegs peg fellie hub Stronger wheels were made by sandwiching two disks with the wood grain crossing at right angles The middle boards of the disks above led to the development of six spoke wheels with rims and large hubs to keep the wheel from wobbling 2012 Encyclopædia Britannica Inc Wheels developed over time They began as rough pieces cut from logs and were made stronger and easier to operate with the use of layered wooden disks followed by spokes pegs and rims simple wheel cut from a log Spoked wheels were stronger and wobbled less but they were suitable only for lighter loads The Roman Empire which covered large parts of Europe northern Africa and the Mediterranean islands needed advanced transportation methods for far flung trade and communications The Romans thus developed vehicles for a variety puppies of
Early Transportation from covered carriages to farm carts as well as light weight racing chariots for entertainment They built a vast paved highway system outward from Rome around two thousand years ago TECHNOLOGY OF INDIGENOUS PEOPLES Although there is no record of the wheel in North or South America before the arrival of Europeans the Incas built a road system through the central Andes Mountains that stretched as far as 2,250 miles 3,624 kilometers The thousands of stone steps on this Inca highway were suitable for human messengers and porters as well as for llamas carrying packs weighing up to about 70 pounds 32 kilograms In North America subarctic tribes made wooden sleds called toboggans to move heavier articles Snowshoes also improved conditions for travelers walking long distances in harsh winter weather American Plains Indians designed a travois a type of sled pulled by people or by sled dogs After the arrival of Europeans Native Americans also began to ride horses and to use them to pull travois 11
The Evolution of Transportation Technology BOAT TRAVEL BEGINS To make boats native peoples of the Americas used materials at hand including dugout tree trunks and animal hides Inuit made animal-skinned kayaks to Native peoples of the Americas such as the Inuit fashioned early boats out of animal skins and tree logs that allowed them to fish farther away from shore 12
Early Transportation fish while American Plains Indians used bullboats wrapping an animal hide over a wooden frame In the Pacific Ocean the Polynesians proved themselves the early master navigators of the world They explored thousands of miles of ocean territory and settled distant islands from New Zealand to Hawaii and Easter Island using canoes which they enlarged and equipped with sails They navigated using the stars knowledge of ocean currents and maps they made from reeds and shells Early Egyptians did not have large trees for dug out canoes instead they constructed cargo ships using smaller pieces of wood tied together which could carry up to 350 tons 317 tonnes of stone The Phoenicians put together planked wooden ships using Lebanon cedar to create vessels with an elab orate ribbed structure Using oars and sail-power on their fleets the Phoenicians controlled trade in the Mediterranean for centuries The Greeks invented the cross-staff and the astrolabe which helped determine location at sea By 1000 CE Viking ships took on a distinctive form with pointed bows and overlapping oak planking called clinker building Vikings also used oarsmen to power their ships 13
