Section 8. An appeal shall lie to the Commissioner from the order of any person authorized, under the power her

8. An appeal shall lie to the Commissioner from the order of any person authorized, under the power hereinafter conferred, to make assessments, in any matter connected with the assessment of any sum leviable under this Act: provided that such appeal be presented within thirty days from the date of the order. The decision of the Commissioner on such appeal shall be final; but all such decisions may be reviewed by the Chief Commissioner.