Built by engineer Adrian Stephens at the Dowlais Ironworks in Merthyr Tydfil. It was a simple safety device to warn engineers when a steam boiler was running out of water which could lead to a ...

Initially Merthyr Tydfil was linked to Cardiff by packhorses carrying pig iron in paniers. A connecting road was built in 1767 but the great innovation was the waterway. By 1800, all the main ...