Found some useful information from the Pennsylvania State Association of Boroughs about the role of a Mayor. In 1834 the first general law regarding boroughs was enacted. The governing body was established, consisting of five councilmen and one burgess. The burgess presided over the council and remained active in borough matters. Over time, the vote of the burgess was restricted to breaking tie votes in most situations of the council.
The late 1800s saw more changes in the role of the burgess. The council was now allowed to vote for its own president, the burgess went from a one year term of office to a four year term of office. In 1893 the borough changed to a city format of government with a weak mayor. In 1961 the term burgess was replaced by the term "mayor" and the council president was given the power to sign important papers and contracts.
The powers of the mayor have diminished over time. Nevertheless, it is still an important positioon in local government. The mayor presides over the reorganization meeting of the council in even numbered years. The Mayor may attend all council meetings. He or she must approve all ordinances of a legislative nature and has the right to veto them if desired. The mayor administers the police department but does not have the power to hire or fire personnel. The mayor may set the schedule for the police officers. Finally, in a ceremonial role, the mayor may officiate marriages in the Commonwealth.