The court of quarter sessions of every county of the Commonwealth, on being petitioned to grant a view for a road within the respective county, shall have power and are hereby required, in open court, to appoint, as often as may be needful, three persons, qualified as hereinafter is provided, to view the ground proposed for such road, and make report of their proceedings to the respective court at the next term thereof: Provided, That the provisions of this act, relative to the appointment of viewers to lay out roads and to assess damages, shall not extend to the city and county of Philadelphia, hereinafter specially provided for.