Many (but not all!) lodges make use of a Bible (either or not replaced or next to another sacred book), also known as the Book of Sacred Law or the Book of Sacred Lore. It is often opened on different places in different degrees and the way the Square and Compasses lay on it, differs per degree as well. These details can differ between lodges. In some lodges the book is replaced by another book, such as the constitution of the Grand Lodge, the Universal Declaration of Human Rights, a symbol book or nothing at all.
Without the Square and Compasses, the Book can be the emblem of the Orator or the Chaplain.
Duncan’s Masonic Ritual and Monitor (1866) by Malcolm C. Duncan