[1] Harper joined the civil service, and in 1864 passed the matriculation examination of the University of Melbourne and graduated BA in 1868.

[5] Harper was a good speaker and debater who exercised much influence in the Presbyterian Church of Australia, and more especially on the candidates for the ministry who studied under him.

Personally he was modest and thoroughly sincere, loyal to the Christian faith yet believing in scientific inquiry, a wise and understanding mentor at a period of transition and reshaping, when many beliefs once firmly held were being attacked.

The Book of Deuteronomy in the Expositer's Bible series, published in 1895, gave him a good reputation, as it was widely recognised as a work of great value.

James Balfour M.L.C., a Memoir, is an interesting record of a leading Melbourne merchant and politician whom Harper had known for nearly 50 years.

A series of lectures to the Sydney University Christian Union was published under the title Christian Essentials; he printed a few pamphlets, and he also contributed the chapter on "The White Australia Policy" to Australia, Economic and Political Studies, edited by Meredith Atkinson and published in 1920.