=Organization of the Two Houses.=--_Officers._--Each house of Congress is free to organize itself in such a manner as it pleases, and to choose its own officers, except that the Vice President of the United States is, by the Constitution, made the presiding officer of the senate. The presiding officer of the house of representatives is called the speaker; that of the senate, the president. Each house has one or more clerks who keep the journals, call rolls, read bills, and have custody of all bills, resolutions, petitions, and memorials; a sergeant-at-arms who preserves order, has charge of the halls, pays members their salaries, and performs various other duties[31]; a postmaster; a doorkeeper; a chaplain; and other minor officials. [31] The sergeant-at-arms of the house of representatives has custody of the mace which is the symbol of the authority of the house. It is a representation of the Roman _fasces_ in ebony, and is surmounted by a globe and an eagle in silver. During the session it is kept in the place provided for it near the speaker's desk, but when disorder breaks out in the course of the debates, the sergeant-at-arms takes the mace from its accustomed place and proceeds, bearing it aloft, to the part of the house where the disorder prevails. He then commands order in the name of the house, and if the display of the mace is not sufficient to restore order, the house may order the disorderly member or members to be arrested. _Opening of a New Congress._--When a new Congress assembles, the house of representatives is called to order by the clerk of the preceding house. He then calls the roll of the members whose credentials or certificates of election have been filed with him, and if a quorum is present the house proceeds to the election of a speaker. The members of each political party represented in the house have already in caucus agreed upon their candidates, and they are now put in nomination before the house by some member representing each party. Usually the action of the caucus of the majority party is equivalent to an election, and the house has only to ratify its choice. In several instances, however, the election of the speaker involved long and bitter contests. Thus in 1849, 63 ballots were taken, and again in 1855-1856, 133 ballots were necessary, and in each case a special rule was adopted permitting a plurality to elect. The senate, on the other hand, is always an organized body. The presiding officer--the Vice President--at the opening of a new Congress calls the senate to order, and the other officers, who hold during the pleasure of the senate, resume their duties. The senate elects one of its own members as president _pro tempore_ to preside over its deliberations during the absence of the Vice President or in case there is no Vice President, as has often happened.