tailieunhanh - An Encyclopedia of the History of Technology part 53

An Encyclopedia of the History of Technology part 53. This one of a kind encyclopedia presents the entire field of technology from rudimentary agricultural tools to communication satellites in this first of its kind reference source. Following an introduction that discusses basic tools, devices, and mechanisms, the chapters are grouped into five parts that provide detailed information on materials, power and engineering, transportation, communication and calculation, and technology and society, revealing how different technologies have together evolved to produce enormous changes in the course of history | PART THREE TRANSPORT by King Charles XII to build a canal from Gothenburg to the Baltic. Unfortunately the king was killed in battle with the Norwegians in the same year and the project languished. A further start on making locks at Trollhätten was made in 1755 but following a landslide that work too was abandoned. However in 1793 a new company took over the construction and on 14 August 1800 the route requiring eight locks at Trollhätten was completed to Lake Vänern. In 1832 the canal was completed from Lake Vänern through Lake Vättern to Söderkoping and the Baltic. The Trollhätten flight was then the restrictive factor on the size of vessels which could traverse the full length of the canal and so a new flight was started there in 1838 and completed in 1844. The 1800 and 1844 flights although on a different alignment were used concurrently until 1916. By the beginning of the twentieth century it was again necessary to provide larger locks. In 1905 the government assumed control of the canal and in 1910 work on a third different alignment was begun. Completed in 1916 it has locks 87m by 41ft with 4m 13ft draught later increased to 15ft . There are three locks in a staircase then a short pound and finally a single lock to raise vessels to the upper level. In the 1970s considerable improvements were made to the fairways on the river and the Göta Canal today carries a steady freight traffic as well as providing a regular passenger service. Also from Lake Vänern leading towards the Norwegian border is Sweden s most beautiful waterway the Dalsland Canal. Constructed between 1865 and 1869 it has 25 locks in its 255km miles length only about 8km are artificial cuts the remainder of the route using natural lakes. At Häverud where there is a canal museum the canal climbs one side of the valley down which a stream cascades. Half-way up the valley the canal crosses the gorge in an iron trough and passes along a ledge cut in the rock face before .