He emigrated to Port Chalmers aboard the Nourmabal, arriving in May 1858, where he began business as a carter and contractor, ferrying goods to the goldfields, and contracting for public works.

Barnes was also appointed inspector of works in 1877, and ultimately mayor in 1885, despite his "crudity of language, hot temper and lack of social graces".

[2] He may be the Inspector of Works Barnes who was reported in a "precarious state" after an assault by another contractor, John Thomson, in 1876.

In 1886, Barnes's son was supervising a blasting operation in Dowling Street which killed two women in their house.

[4] Barnes died in Dunedin on 18 November 1889, having failed to recover from internal injuries received from a fall from a horse at Milton 18 months earlier.