Col. Sir David Harris was born in London in 1852 under that name. Barney was his first cousin and born the same year in London. In his memoir Pioneer Soldier and Politician, David writes that he arrived in Durban in 1871 and made his way, on foot, to was to become Kimberley, not Namibia. Barney only arrived there in 1873. Sir David was married to my grandmother's cousin, Rosa Gabriel.
All the best,