The composer of this famous old hymn is P. P. Bliss. Follow this link to know more about the hymn: https://hymnary.org/text/brightly_beams_our_fathers_mercy and this link to learn about the Bliss, himself: https://hymnary.org/person/Bliss_Philip. I remember, so clearly, as a small boy hearing my mother and father playing this in our front room (my father on piano, my mother on violin) as I fell asleep on the front room couch.