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.
The main corridor running the entire length of the building upon this floor, with an exit to the marble terrace at either end, is nearly 750 feet in length.
The first door upon the right, to the south of the annex which connects the old building with the Senate extension, leads to the private consultation room of the justices of the Supreme Court of the United States. Here they meet and consult before promulgation of their decisions. The room, similar to most of the committee rooms, contains a long consultation table with chairs about, but no decoration worthy of mention. It is never open to the public; and every precaution is taken to guard from foreign ears not only the councils in this chamber, but the final determinations of that learned body before they are pronounced in open Court. Saturday is the consultation day. It is only on rare occasions, of late years, that the justices find it necessary to consult at night, as was common in the earlier days of the Court, when four or five evening consultations were held during a week. Before the present chamber was fitted up, the justices met in a room convenient to their residences.