An Encyclopedia of the History of Technology part 60. 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 Of greater importance even than effective signals for railway operating was the electric telegraph which fortuitously was brought to practical form by William and Charles Wheatstone see p. 714 at precisely the period that the first trunk railways were being built. Cooke carried out successful experiments alongside the London Birmingham Railway between Euston and Camden Town in 1837 and although the L B company did not take up the telegraph at that time the following year at the instance of Brunel the Great Western decided to do so. The electric telegraph was completed between Paddington and West Drayton in 1839 and subsequently extended and it was used to pass messages of all sorts from requests for horses to be available for passengers on arrival at Paddington to notifying the presence of a suspicious character on a train which led to his arrest for murder. The electric telegraph was first used to control train operations in 1840 on the London Blackwall Railway opened that year. This line was worked by reciprocating cable haulage when coaches standing at the stations had been connected to the cable the stationary engine driver was telegraphed that it was safe to start winding. The following year 1841 the electric telegraph was installed through Clayton tunnel London Brighton Railway between signalmen at each end with instructions not to let a train enter until the previous train had emerged. This was the first instance of the block system of trains separated by an interval of space rather than time. Other installations were soon made through tunnels and on cable-worked inclines. The Norwich Yarmouth Railway opened in 1844 was the first railway to be worked throughout by the block system using the electric telegraph on principles developed by Cooke and because of this it had been possible to build it as a single line with passing loops. That was an economy but in general the installation of a full electric telegraph system on an .
