For many years it had been thought he died in Australia in 1902, but there has never been any documentary evidence to back that up. I decided to start from scratch, examining his life step by step, but the biggest and most obvious clue was that he showed up in a search in the 1911 census. The fact that he had a wife and two children - not the same wife and children he had 20 years earlier - just made the research more challenging and interesting. I found his first wife had died age 22, leaving their son and daughter to be brought up in Glasgow with their grandparents. Watson married again, had two more children, and lived in Liverpool and finally London, where he died in 1921.
A fascinating element of his story is that he was the product of a Scottish planter and a Guyanan woman. His father, Peter Miller Watson, was a former slave owner who was compensated by the British Government for the freedom of his slaves in the 1830s; so when he left £35,000 in his will to Andrew Watson and his sister Annetta, giving them financial security for life, much of their fortune derived from the misery of slavery. Little is known about his mother, whose name is given as Anna Rose on his first marriage certificate and Hannah Rose on his second; but as one of his father's wealthy business associates was called Peter Rose, possibly she was linked to his household.
I have yet to visit Watson's grave, but will do so next time I am in London. Meanwhile, if anyone else would like to go to Richmond Cemetery and take a photo or leave a bunch of flowers, it is in Section 4, grave plot No 6321.