The Manual of The Mother Church, first issued in 1895 and revised through eighty-nine editions to 1910, is a constitution that its author made unamendable. Several by-laws require the written consent of Mary Baker Eddy before an action may be taken — the estoppel clauses — and since 1910 that consent has been unobtainable, which means the provisions are permanently frozen. Authority sits with the Christian Science Board of Directors, five members who fill their own vacancies, in Boston. Branch churches are democratically self-governing and financially independent, but may not employ a preacher, may not publish membership numbers, and take their lesson from Boston. The structure is why the church has been stable and why it has been unable to adapt: the 1980s Board's expansion into television and the resulting financial crisis, and the long fight over the posthumous publication of Bliss Knapp's Destiny of The Mother Church, were both fought over what the Manual permitted.