On December 15, 1884, the society was incorporated as Zion's Watch Tower Tract Society in Pennsylvania as a non-profit, non-stock corporation with Russell as president. The corporation was located in Allegheny, Pennsylvania. In its charter, written by Russell, the society's purpose was stated as "the mental, moral and religious improvement of men and women, by teaching the Bible by means of the publication and distribution of Bibles, books, papers, pamphlets and other Bible literature, and by providing oral lectures free for the people". The charter provided for a board of seven directors, three of whom served as officers—a president, vice-president (initially William I. Mann) and secretary-treasurer (initially Maria Russell). The charter stipulated that the officers be chosen from the directors and be elected annually by ballot. Board members would hold office for life unless removed by a two-thirds vote by shareholders. Vacancies on the board resulting from death, resignation or removal would be filled by a majority vote of the remaining board members within 20 days; if such vacancies were not filled within 30 days an appointment could be made by the president, with the appointments lasting only until the next annual corporation meeting, when vacancies would be filled by election.