He was a good Latinist, Tacitus being his favourite author; his Greek was thin; he was somewhat given to rabbinical studies, having collected a small store of learned books on this subject.
[1] When Lord Glerawley disarmed the Rathfriland regiment of volunteers in 1782, the officers and men chose Barber as their colonel in his stead.
He sat in the three volunteer conventions of 1782, 1783, and 1793, as a strong advocate of parliamentary reform, catholic emancipation, and a revision of the tithe system, the revenue laws, and the Irish pension list.
In 1786 Richard Woodward, Bishop of Cloyne, published his Present State of the Church of Ireland, to prove that none but Episcopalians could be loyal to the constitution.
Barber's Remarks in reply showed him a master of satire, and embodied the most trenchant pleas for disestablishment that any dissenter had yet put forth ("Must seven-eighths of the nation for ever crouch to the eighth?").
For an incident of his pastoral experience, turning on the difficulties of the then Irish marriage law, can be found in the autobiography of Catherine Cappe.
[2] Montgomery assigns to him "a singularly vigorous mind, a cultivated taste, a ready wit, a fluent elocution, a firm purpose, an unsullied character, and a most courteous demeanour.