1834 1913 This tablet raised by public subscription commemorates one of the earliest pioneers of wireless telegraphy Sir William Henry Preece K.C.B. F.R.S. Engineer-in-Chief to the Post Office A native and first honorary freeman of Caernarvon. He was amongst the foremost of pioneers in the development of wireless telegraphy and one of the first to experiment successfully with the sending of the spoken word through space. Arloesydd Ynglyn a holl ddatblygiadau cynnar y radio yn Y wlad hon a thros y moroedd

English translation: "1834 1913 This tablet raised by public subscription commemorates one of the earliest pioneers of wireless telegraphy Sir William Henry Preece K.C.B. F.R.S. Engineer-in-Chief to the Post Office A native and first honorary freeman of Caernarvon. He was amongst the foremost of pioneers in the development of wireless telegraphy and one of the first to experiment successfully with the sending of the spoken word through space. Arloesydd Ynglyn a holl ddatblygiadau cynnar y radio yn Y wlad hon a thros y moroedd [Google Translate]"
Elliott Brown on Flickr
Siaron James from Caernarfon, Wales on Wikimedia Commons
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