HERBERT R. O'CONOR, GOVERNOR. 687

517. The County Commissioners shall determine the man-
ner in which regulations and restrictions, and the boundaries
of such districts, shall be established and enforced, and from
time to time amended, supplemented and changed. Before
determining the boundaries of the proposed districts and the
regulation to be enforced therein, they shall hold a public
hearing or hearings thereon, giving at least fifteen days notice
in a newspaper of general circulation throughout the County^
of the place and time of the beginning of such hearing or hear-
ings. The County Commissioners shall have power to amend,
supplement or repeal the regulations or restrictions adopted
by them, provided that before doing so they shall follow the
same procedure with respect to notice and public hearings
as is herein provided for the original regulations and restric-
tions.

518. The County Commissioners are hereby vested with
such duties and powers as may be necessary and advisable for
the proper administration of this sub-title and of such zoning
regulations as they may adopt under the provisions of this
sub-title, including the power to make general exceptions to
permit continuance of existing uses and to permit limited
trade or commercial uses of designated streets or blocks within
residence areas, and including the power to summon and com-
pel the attendance of witnesses.

519. Any person, persons, taxpayer, officer, department,
board or bureau of the County, jointly or severally aggrieved
by any decision of the County Commissioners of Anne Arun-
del County, may, within thirty days after the filing of such
decision in the office of the County Commissioners, appeal to
the Circuit Court for Anne Arundel County.

The said Court shall hear all such appeals de novo and shall
have power to affirm the decision of the County Commission-
ers of Anne Arundel County, or reverse the same, in whole or
in part, and may remand any case for the entering of a proper
order or for further proceedings, as the Court shall determine.

All issues in any proceeding under this sub-title shall have
preference over all other civil actions andr proceedings.

520. The County Commissioners shall keep in a separate
book all rules, regulations and restrictions adopted by them
from time to time under the authority of this sub-title, and
any amendments or supplements thereto, and shall cause
copies to be printed and made available for general distribu-
tion. Any such printed copy, together with any amendments
and supplements, when certified as accurate by the Chief Clerk
of the County Commissioners, shall be deemed prima facie evi-
dence thereof in any judicial proceeding in the State,