Sir William Henry Preece was a Welsh electrical engineer and inventor. Preece relied on experiments and physical reasoning in his life's work. Upon his retirement from the Post Office in 1899, Preece was made a Knight Commander of the Order of the Bath (KCB) in the 1899 Birthday Honours. That same year, he was elected an International Member of the American Philosophical Society.

Caernarfon is a royal town, community and port in Gwynedd, Wales. It has a population of 9,852. It lies along the A487 road, on the eastern shore of the Menai Strait, opposite the island of Anglesey. The city of Bangor is 8.6 miles (13.8 km) to the north-east, while Snowdonia (Eryri) fringes Caernarfon to the east and south-east.