<P> Each senator chooses a desk based on seniority within the party . By custom, the leader of each party sits in the front row along the center aisle . Forty - eight of the desks date back to 1819, when the Senate chamber was reconstructed after the original contents were destroyed in the 1812 Burning of Washington . Further desks of similar design were added as new states entered the Union . It is a tradition that each senator who uses a desk inscribes their name on the inside of the desk's drawer . </P> <P> Except for the President of the Senate, the Senate elects its own officers, who maintain order and decorum, manage and schedule the legislative and executive business of the Senate, and interpret the Senate's rules, practices and precedents . Many non-member officers are also hired to run various day - to - day functions of the Senate . </P> <P> Under the Constitution, the vice president serves as President of the Senate . He or she may vote in the Senate (ex officio, for he or she is not an elected member of the Senate) in the case of a tie, but is not required to . For much of the nation's history the task of presiding over Senate sessions was one of the vice president's principal duties (the other being to receive from the states the tally of electoral ballots cast for president and vice president and to open the certificates "in the Presence of the Senate and House of Representatives," so that the total votes could be counted). Since the 1950s, vice presidents have presided over few Senate debates . Instead, they have usually presided only on ceremonial occasions, such as joint sessions, or at times to announce the result of significant legislation or nomination, or when a tie vote on an important issue is anticipated . </P> <P> The Constitution authorizes the Senate to elect a president pro tempore (Latin for "president for a time") who presides over the chamber in the vice president's absence, and is, by custom, the senator of the majority party with the longest record of continuous service . Like the vice president, the president pro tempore does not normally preside over the Senate, but typically delegates the responsibility of presiding to a majority - party senator who presides over the Senate, usually in blocks of one hour on a rotating basis . Frequently, freshmen senators (newly elected members) are asked to preside so that they may become accustomed to the rules and procedures of the body . It is said that, "in practice they are usually mere mouthpieces for the Senate's parliamentarian, who whispers what they should do". </P>

When does the president of the senate vote