It was probably John Walters who persuaded Rhys Thomas, printer (q.v.), to set up at Cowbridge the first printing press in Glamorgan. He published A Dissertation on the Welsh Language, 1771, and Dwy Bregeth, 1772, but his chief work was the large English-Welsh dictionary. This was based on the unpublished dictionary of William Gambold (q.v.), but Walters was assiduous in collecting material of all kinds. The work was printed at the Cowbridge press, part one appearing on 5 April 1770. Fourteen parts were issued between 1770 and 1783, but the remainder could not be printed until 1794, when Owen Jones (Owain Myfyr, q.v.) arranged for the work to be completed in London. Walters coined a large number of words which have become established in the Welsh vocabulary, and he sought to show how to translate English idioms into Welsh. Two editions were published during the last century and this was the work which Daniel Silvan Evans (q.v.) had at his elbow when he was compiling his English-Welsh dictionary.