Above: Slate Worker, Portland stone, National Museum of Wales, Cardiff, 1964.
Above: Jonah and his assistant Gordon Jones on the Porthmadog harbour quay carving the figures for the National Museum of Wales, Cardiff. (Unknown photographer.)
Jonah spent several months in 1964 working on two great figures of Melangell, representing nature and agriculture, and a slate worker, representing industry, for the west wing of the National Museum, fulfilling the original plans for the building drawn up in 1912. They were by far the largest figures he ever carved. The two 18.5-ton blocks of stone had to be transported by sea direct from the Isle of Portland to the quay at Porthmadog, where they were lifted ashore by the crane set up for bringing in materials for the construction of Trawsfynydd atomic power station. No building locally could take the huge monoliths, so Jonah and his assistants had to work out in the open air right there on the quay.