where did the office of senior deacon come from in craft masonry and what are his duties

The office of Deacon was not present in the earliest eighteenth-century rituals, where its functions were divided between the Junior Warden and the Senior and Junior Entered Apprentices 1. It entered English practice at the Union of 1813, having been adopted from the "Antients," who derived the office from Irish usage 1.

W. J. Chetwode Crawley notes a distinction between the Deacon of early Scottish lodges—who occupied the highest post among his brethren and presided over meetings—and the Irish Deacon, whose title reflected the ecclesiastical office of the ministry 1. Albert C. Mackey suggests an even older parallel in the early Christian church, where deacons or acolytes served as doorkeepers to regulate entry 1.

In the lodge, the charge of candidates is placed in the hands of the Deacons 2. Arthur Edward Waite notes that they are attached to the Master and Wardens in a peculiar manner, carrying the dove as their characteristic emblem 2. The Senior Deacon specifically takes charge of the inner door of the lodge 1. All legal communications between the interior and exterior must pass through the door under his charge, opened only after a regular alarm is reported and upon the order of the Worshipful Master 1.

Like the Senior Deacon, the office of Junior Deacon was not part of the earliest eighteenth-century rituals, where its functions were divided between the Junior Warden and the Entered Apprentices 1. The office entered mainstream English practice through the Antients, who had adopted it from Irish usage, and it was formally incorporated at the Union of 1813 1. Broadly, the Masonic deaconate draws its historical parallel from the early Christian church, where deacons and subdeacons were assigned to guard the doors and regulate entry 1.

The principal duty of the Junior Deacon is the charge of the lodge's outer door, working in tandem with the Senior Deacon, who oversees the inner door 1. He controls communication between the lodge room and the outside, ensuring that no message or report passes across the threshold except through the door itself after a regular alarm has been duly reported and answered on the order of the Worshipful Master 1. In some lodge rooms, a small aperture in the outer door permits direct communication between the Junior Deacon and the Tiler, though this practice has been criticized as an unnecessary modern variation on traditional lodge security 1.