from the book "THE PRINCIPLES OF MASONIC LAW"
A Treatise on the Constitutional Laws, Usages And Landmarks of Freemasonry
by Dr.Albert Gallatin Mackey, 1856
The Senior and Junior Warden are the assistants of the Master in the government of the lodge. They are selected from among the members on the floor, the possession of a previous office not being, as in the case of the Master, a necessary qualification for election. In England they are appointed by the Master, but in this country they are universally elected by the lodge.
During the temporary absence of the Master the Senior Warden has the right of presiding, though he may and often does by courtesy, invite a Past Master to assume the chair. In like manner, in the absence of both Master and Senior Warden, the Junior Warden will preside and competent Brethren will by him be appointed to fill the vacant seats of the Wardens. But if the Master and Junior Warden be present and the Senior Warden be absent, the Junior Warden does not occupy the West, but retains his own station, the Master appointing some Brother to occupy the station of the Senior Warden. For the Junior Warden succeeds by law only to the office of Master and, unless that office be vacant, he is bound to fulfill the duties of the office to which he has been obligated.
In case of the death, removal from the jurisdiction, or expulsion of the Master, by the Grand Lodge, no election can be held until the constitutional period. The Senior Warden will take the Master's place and preside over the lodge, while his seat will be temporarily filled from time to time by appointment. The Senior Warden being in fact still in existence and only discharging one of the highest duties of his office, that of presiding in the absence of the Master, his office cannot be declared vacant and there can be no election for it. In such case, the Junior Warden, for the reason already assigned, will continue at his own station in the South.
In case of the death, removal, or expulsion of both Master and Senior Warden, the Junior Warden will discharge the duties of the Mastership and make temporary appointments of both Wardens. It must always be remembered that the Wardens succeed according to seniority to the office of Master when vacant, but that neither can legally discharge the duties of the other. It must also be remembered that when a Warden succeeds to the government of the lodge, he does not become the Master, he is still only a Warden discharging the functions of a higher vacated station, as one of the expressed duties of his own office. A recollection of these distinctions will enable us to avoid much embarrassment in the consideration of all the questions incident to this subject. If the Master be present, the Wardens assist him in the government of the lodge. The Senior Warden presides over the craft while at labor and the Junior when they are in refreshment. Formerly the examination of visitors was intrusted to the Junior Warden, but this duty is now more appropriately performed by the Stewards or a special committee appointed for that purpose.
The Senior Warden has the appointment of the Senior Deacon and the Junior Warden that of the Stewards.