The ordinary and permanent office‑bearers of the church were of four kinds: the minister, or pastor, to whom the preaching of the gospel and administration of the sacraments belonged; the doctor, or teacher, whose province it was to interpret scripture and confute errors (including those who taught theology in schools and universities); the ruling elder, who assisted the minister in exercising ecclesiastical discipline and government; and the deacon, who had the special oversight of the revenues of the church and the poor. But, besides these, it was found necessary, at this time, to employ some persons in extraordinary and temporary charges. As there was not a sufficient number of ministers to supply the different parts of the country, that the people might not be left altogether destitute of public worship and instruction, certain pious persons, who had received a common education, were appointed to read the scriptures and the common prayers. These were called _readers_. In large parishes, {7} persons of this description were also employed to relieve the ministers from a part of the public service. If they advanced in knowledge, they were encouraged to add a few plain exhortations to the reading of the scriptures. In this case they were called _exhorters_; but they were examined and admitted, before entering upon this employment. The same cause gave rise to another temporary expedient. Instead of fixing all the ministers in particular charges, it was judged proper, after supplying the principal towns, to assign to the rest the superintendence of a large district, over which they were appointed regularly to travel, for the purpose of preaching, of planting churches, and inspecting the conduct of ministers, exhorters, and readers. These were called _superintendents_. The number originally proposed was ten; but, owing to the scarcity of proper persons, or rather to the want of necessary funds, there were never more than five appointed.[12] The deficiency was supplied by commissioners, or visitors, appointed from time to time by the General Assembly.