It was from Roberton's Songs of the Isles (Vocal Edition: J. Curwen and Sons, apparently 1950).  I neglected to give the copyright date for the song, which is 1934 (USA).  There are twenty songs, mostly in English, largely based on traditional tunes, most -but not all- with input from Roberton as lyricist or arranger, including Mingulay Boat Song, Lewis Bridal Song (Mairi's Wedding) and so on.