This section is from the book "The National Capitol. Its Architecture Art And History", by George C. Hazelton, Jr. Also available from Amazon: The National Capitol Its Architecture Art and History.
An excellent view of the Senate Chamber is to be had from any one of its galleries, the seating capacity of which is 690 persons. The chamber is rectangular in shape, being 113 feet 3 inches in length, 80 feet 3 inches in width and 36 feet in height. The hall and its adjoining private lobbies are richly furnished. The Vice-President of the United States, who, as part of his Constitutional duties, presides over the Senate, occupies the chair upon the rostrum in the center to the north. On his right sits the Sergeant-at-Arms ; on his left, the Doorkeeper. The long table before the chair is for the use of the Secretary of the Senate, the reading clerks, the chief clerk and the journal clerk. The small mahogany tables in front of the Secretary's table are devoted to the official stenographers, who report all debates and other proceedings, otherwise than during executive sessions, that take place upon the floor of the Senate. The center aisle customarily divides the seats occupied by the two great political parties. On the right of the presiding officer sit the Democrats; upon his left, the Republicans. Third-party men usually sit upon the side of the chamber where their affiliations have theretofore been. The Senators' desks all conform to the same general model 12 in appearance, though many of them are very old, having been brought from the former chamber.