 In 1946 he semi-retired from business, and devoted his life to his scientific and cultural interests, and fishing.This was the year in which he published "Country Sonnets", which included many poems written in the Orkney dialect.Rendall became a friend of the writer George Mackay Brown, whom he encouraged, and who had appreciated the quality of his best poetry, having been introduced to him by Ernest Marwick Brown was encouraged by Rendall's visits when he was confined to Eastbank Sanatorium.