[1] Blackmann had a spectacular fall from grace in 1886 when he sailed to California with a younger woman, abandoning his wife, seven children and new business partner (Sir) John Sulman.

[2][3] During his lifetime, Blackmann's contemporaries lauded his skills[citation needed] in mining engineering, drawing, design, project management and architecture.

Born to German parents in Tomaszów[note a] in the Russian Protectorate of Poland in April 1835, Blackmann was educated in Berlin, after which trained under the Continental builder/architect method, articled to an architect with practical experience as a carpenter.

He built the first puddling machine in Tasmania and 'managed to extract some 17,000 to 20,000 grams (600 to 700 oz) of gold from a surface run of alluvial wash a little more than from 3.7 to 4.6 metres (12 to 15 ft) deep'.

[11] Privately he was the architect of the heritage-listed German Lutheran Trinity Church in Parliament Place, East Melbourne, which opened in November 1874.

The partnership flourished for over five years until dissolved in September 1885, when Varney Parkes was elected to the New South Wales Parliament.

[18] The 1883 design of the Victorian Free Classical style Erskinville Public School is jointly attributed to Blackmann and Parkes.

[19] Also in 1880, Blackmann designed his home Oybin, part of the Johnston Street Group built by John Young in the Sydney suburb of Annandale.

[22] It would appear that Blackmann, then aged 51 suffered a 'mid life crisis' and sailed for New Zealand from Melbourne on SS Waihora on 2 December 1886.