The Guest Family
John Guest was an Englishman from Broseley, Staffordshire, and arrived in Merthyr Tydfil in 1759 to act as manager of the "Myrthy Furnace." So efficient was he that he was soon given sole charge of the furnace, while Thomas Lewis saw to the transport of the iron to Cardiff. Under the careful management of John Guest, the work prospered,and he became a partner in the firm. As the business grew rapidly, the Dowlais Iron Company was formed in 1759.By the time of Guest's death in 1785, the production of iron had trebled from the 500 tons a year in 1759.
Thomas Guest succeeded his father as manager, and held the position until his death in 1807. He was the first to introduce steam power into the district, in 1795, and was responsible for the opening of a Company, or Truck Shop, in 1797. Like his father, he was a tireless worker. The works increased in size and the output became much greater,so that in 1800 there were three furnaces working, and these produced 3,000 tons of iron in a year. He was deeply religious and helped to establish the Wesleyan Methodist cause in the district. As a lay preacher he often officiated at the chapels in the neighbourhood.
John Josiah Guest was the next manager and he, too, put all his energy into the work. It is said that he mastered his work so thoroughly that he could cut coal and roll iron as skilfully as the best craftsman.
The output continued to increase rapidly. In 1815 there were five furnaces in blast, and 16,000 tons of iron were manufactured in a year. Thirty years later, in 1845, over 7,000 workpeople were employed, and 75,000 tons of iron were made in the 18 furnaces, and sent to Cardiff for export.
Sir John Guest was the last of his family to take an active,personal interest in the works. His wife was Lady Charlotte Guest, the famous translator of the Mabinogion.