The Board shall have power to adjourn from day to day for a term not exceeding fifteen days. In case all the certified statements for the election of electors for President and Vice-President shall not have been received on the day set for the meeting of the Board, the Board may adjourn from day to day until the same shall have been received, not exceeding five days; and if at the expiration of four days certified copies of the statements of the county canvassers shall not have been received from any county, the Board shall proceed to canvass upon such of the statements as shall have been received.