Editing Glamorgan (section)

=====Coal industry=====
The largest change to industrial Glamorgan was the opening up of the [[South Wales coalfield]], the largest continuous coalfield in Britain, which occupied the greater part of Glamorgan, mostly north of the Vale.<ref name="Davies, p.153">Davies (2008), p.153</ref> The coalfield provided a vast range in quality and type, but prior to 1750 the only real access to the seams was through [[bell pit]]s or digging horizontally into a level where the seam was exposed at a river bank or mountainside.<ref name="Davies p.154">Davies (2008), p.154</ref> Although initially excavated for export, coal was soon also needed for the smelting process in Britain's expanding metallurgical industries. Developments in coal mining began in the north-eastern rim of Glamorgan around the ironworks of Merthyr and in the south-west around the copper plants of Swansea.<ref name="Davies p.154"/> In 1828 the South Wales coalfield was producing an estimated 3 million tons of coal, by 1840 that had risen to 4.5 million, with about 70 percent consumed by local commercial and domestic usage.
[[File:Lewis Merthyr Colliery.jpg|thumb|right|250px|Lewis Merthyr Colliery, Rhondda which, since 1986, has been redeveloped for opening to the public as the [[Rhondda Heritage Park]].]]
The 1840s saw the start of a dramatic increase in the amount of coal excavated within Glamorgan. Several events took place to precipitate the growth in coal mining, including the discovery of steam coal in the [[Cynon Valley]], the building of a large masonry dock at Cardiff and the construction of the [[Taff Vale Railway]].<ref name="Davies p.154"/> In 1845, after trials by the [[British Admiralty]], Welsh steam coal replaced coal from [[Newcastle-upon-Tyne]] as the preferred fuel for the ships of the [[Royal Navy]]. Glamorgan steam coal quickly became a sought-after commodity for navies all over the world<ref name="Davies p.154"/> and its production increased to meet the demand.

The richest source for steam coal was the Rhondda Valleys, and by 1856 the Taff Vale Railway had reached the heads of both valleys. Over the next fifty years the Rhondda would grow to become the largest producer of coal of the age. In 1874, the Rhondda produced 2.13 million tons of coal, which rose to 5.8 million tons by 1884.<ref name="Davies p.154"/> The coal now produced in Glamorgan far exceeded the interior demand, and in the later half of the 19th century the area became a mass exporter for its product. In the 1890s the docks of South Wales accounted for 38 percent of British coal exports and a quarter of global trade.<ref name="Davies p.154"/>

Along with the increase in coal production came a very large increase in the population, as people emigrated to the area to seek employment. In Aberdare the population grew from 6,471 in 1841 to 32,299 in 1851 while the Rhondda grew from 3,035 in 1861 to 55,632 in 1881, peaking in 1921 at 162,729.<ref name="Lewis229-230">Lewis (1959), pp.229–230</ref> Much of this population growth was driven by [[immigration]]. In the ten years from 1881 to 1891, net migration to Glamorgan was over 76,000, 63 percent of which was from the non-border counties of England – a proportion that increased in the following decade.<ref>D. Gareth Evans (1989), p.241</ref>