Among his publications were the well-known quarterly magazine Y Traethodydd (" The Essayist"), Gwyddoniadur Cymreig (" Encyclopaedia Cambrensis"), and Dr Silvan Evans's English-Welsh Dictionary (1868), but his greatest achievement in this field was the newspaper Baner Cymru (" The Banner of Wales"), founded in 1857 and amalgamated with Yr Amserau (" The Times") two years later.