Paragraph 6
The chairman and other members of the Board shall hold office for such period of not more than 5 nor less than 3 years as the Secretary of State may determine; but any member—
(a)
shall be eligible for re-appointment from time to time on or after the expiration of his term of office ; and
(b)
may by notice in writing to the Secretary of State resign office at any time, while remaining eligible for re-appointment.