When Rutherford died in 1942, Nathan H. Knorr became the new president. Two years later he changed the words in the charter, or society's rules, to say that its main purposes were to preach about God's kingdom to people in all countries, and print and share Bibles and other books and magazines that would help them learn about that. The rules about who could be a member of the society were also changed, making it open only to a maximum of 500 men who would be chosen by the leaders of the society. Knorr died in 1977 and since then the presidents have been Frederick W. Franz, Milton G. Henschel and Don A. Adams.