Originally a railway engineer, Girleston had been Chief Engineer to the Bristol Dock Estate before taking up painting in his later years, and spending time in both Norway and Cornwall. The artist is mentioned in the biographical essay prepared by the family of Brian HATTON, as one of the artists which Hatton visited in Cornwall in 1903 in order to obtain critical comment upon his work.

John worked from the St Eia Studio up until 1911, and showed a number of Norwegian scenes in watercolours on the Show Day of that year. The St Ives Times reported his death with the headline 'Sudden Death at Carbis Bay' when he died at his home, 'The Nest' at Carbis Bay at the age of 71.