An Encyclopedia of the History of Technology part 25. 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 ONE MATERIALS Progress patented the making of sulphuric acid by burning sulphur and saltpetre in the necks of large glass globes containing a little water. That was converted to sulphuric acid concentrated by distilling it. The price fell from 2 to 2s a pound but the fragile nature of glass limited the scale of the process. Largescale manufacture only became possible when John Roebuck substituted lead chambers consisting of sheets of lead mounted on wooden frames lead being both cheap and resistant to the acid. Roebuck a student of chemistry at Leyden and Edinburgh set up his lead-chamber process outside the latter in secrecy a condition that lasted as long as it usually does. Knowledge of the process spread rapidly France had its first lead-chamber factory at Rouen around 1766. The process was improved and enlarged in scale Roebuck s chambers had a capacity of 200ft3 but by 1860 Muspratt had achieved one of 56 000ft3 . The rise in scale of course lowered the price by 1830 it was 2 1 2d a pound. The first stage of the Leblanc process produced large quantities of hydrochloric acid gas both poisonous and destructive. Not for the first or last time the chemical industry made itself unpopular by its unfortunate environmental effects. In this case from 1836 the gas began to be absorbed by a descending stream of water. The Alkali Act of 1863 required manufacturers to absorb at least 95 per cent of the acid. Important as the Leblanc process was it had other drawbacks principally the problem of disposing of the unpleasant galligu or residue after the soda had been extracted. This led to a long search for an alternative and the gradual emergence of the ammonia-soda process which eventually achieved success at the hands of the Belgian brothers Ernest and Alfred Solvay with a patent in 1861 and satisfactory working four years later. It was introduced into Britain in 1872 by Ludwig Mond who set up a works at Winnington in Cheshire in partnership withJohn .
