45.Section 16 provides that if there is a vacancy in the office of Lord Chief Justice, or if he is incapacitated, the functions of the Lord Chief Justice may be exercised by the Master of the Rolls or the next most senior Head of Division, as set out in subsection (3). If any of these offices are themselves vacant the functions may be exercised by the next most senior Head of Division as specified in the section. Any decision as to whether the Lord Chief Justice is incapacitated, or has ceased to be incapacitated, must be agreed in writing by at least three of the four Heads of Division.