Samwell was deeply interested in letters — he read Horace during the voyage with Cook — and in Welsh culture in particular. He was author of several pieces of occasional verse both in English and Welsh — for example, an englyn written when the Resolution reached the Cape of Good Hope on the outward journey, pennillion written on S. Davids Day, 1777 , when he was at sea between New Zealand and Tahiti , etc., and particularly, ‘ The Padouca Hunt ’ in which he made his witty contribution to the controversy as to whether a Welshman named Madoc had discovered America before Columbus and was the progenitor of a tribe of Welsh-speaking Missouri Indians (further details are given in the major article noted in the bibliography below).

Of greater importance than his verse was the support which he gave to Welsh cultural organisations . He was one of the earliest members ( 1774 ) of the Gwyneddigion Society founded in 1770 , became its secretary in 1788 , and its president in 1797 . He supported the ‘Gorsedd’ held in the capital for London Welshmen and the eisteddfodau promoted in Wales by the society; at the latter, his blind partisan support of the claims of Thomas Edwards ( Twm o'r Nant , q.v.) , whom he idolised, appeared to reveal a headstrong and intolerant nature. He assisted in the task of collecting for publication the poems of Dafydd ap Gwilym and of Huw Morys . A portrait of Samwell is reproduced in the first article noted below.