Robert Orr Muir married William's mother on 23 June 1871 and the blended family included Robert's three living children from his first marriage to Jane Paton Loudon, his new wife, Mary Watson Shaw, William, and William's half-sister, Margaret McNeil Shaw, also illegitimate. Robert and Mary produced nine of their own children between 1872 and 1887.
In 1878, at the age of 12, William followed his step-father Robert into the coal mines. He worked at the Auchlochan Mine near Coalburn. On 5 October 1878, William was ascending shaft of the No. 2 pit, known as "Major Pit;" when he fell out of the cage, used to raise and lower the miners; and sustained fatal injuries. He survived 18 hours after the accident but died the next day at the home of his mother and step-father.
|From the Register of Corrected Entries for William Brown Shaw's|
death registration; source ScotlandsPeople
His step-father registered his death with the parish office on 7 October. He provided "Andrew Brown, farmer (reputed father)" to the registrar -- the first and only time a possible father was mentioned in records. Prior to her marriage, Mary Shaw worked as a domestic servant at the 270-acre Auchenheath Farm, owned by William Braxter. He employed several domestic and farm servants and I have often wondered if that is where she met William's father.