Chairman shall betheperiodofhisoffice as a member of the Board.(7) The chairman of any meeting of the Board shall, in addition to his own vote, have a casting vote.Seal of the Bureau.13. (1) The seal of the Bureau shall be in the custody of the Board or any officeroftheBureauauthorizedinthatbehalf by such Board.(2) The seal of the Bureau may be altered in such manner as may be determined by the B