where did the office of chaplain come from in the craft and what are his duties

The office of Grand Chaplain was instituted on 1 May 1775 on the occasion of laying the foundation stone of Freemasons' Hall in London 1. Although the English Constitutions of 1784 note that the office was revived on that day after having been discontinued for several years, no record exists of any appointment prior to 1775 1. Within individual lodges under American ritual practice, the office is not formally recognized in the ritual—though often conferred by courtesy—and the Master generally performs the chaplain's duties himself 1.

The Chaplain's role centers on devotional leadership. All lodge meetings begin and end with prayer, led by the Chaplain, as singletonlodge.org.uk notes. The Chaplain also delivers the Oration during the Consecration Ceremony of a lodge, as an article on the Grand Lodge of India's website notes, and leads hymns and prayers at Masonic multi-faith services, as an article on the United Grand Lodge of England's website notes. When a qualified Brother temporarily presides over the Lodge, the Chaplain sits on the immediate left of the Immediate Past Master, as the United Grand Lodge of England states.

When the office of Grand Chaplain was created in 1738, it was established as an appointed position, filled annually by the Grand Master 1.

Regarding individual lodges, the available sources do not provide a general history of local lodge chaplain elections versus appointments, noting only that in American ritual practice the office of lodge Chaplain is not formally recognized in the ritual itself—though often conferred by courtesy—with the Master generally performing those duties 1.