2. The mansion house known as "Salona" as such structure exists at the date of the execution of this instrument, shall not be razed, demolished, moved or relocated until such action is approved by the Board of County Supervisors acting upon the advice of the Architectural Review Board as provided for in Section 30-2A.2 of the Code of Fairfax County or until such structure becomes uninhabitable or demolished through fire, storm or similar natural calamity. 3. No commercial or industrial use shall be commenced or allowed to continue, unless expressly permitted in (A) above or in any duly executed and recorded amendment hereof. 4. No sign, billboard, or other display shall be erected or allowed to remain on the property described herein, provided, that one sign of a size not greater than 25 square feet advertising the sale of the property or the products or activities available thereon may be erected. 5. No major grading or topographic change shall be accomplished except by express permission, in writing, from the Director of County Development of Fairfax County, or the successor to his duties. Such permission shall only be granted in accordance with a grading plan prepared by or at the direction of the grantor or his successor in interest and approved by Fairfax County. Major grading shall be deemed to mean any grading performed by machine, other than hand-operated machines. 6. No trees or shrubbery over 8 inches in diameter measured 5 feet above ground shall be cut down or removed except by express permission, in writing, from the Director of County Development of Fairfax County, or the successor to his duties, provided, however, that management of existing trees, shrubs or other vegetation, including trimming and removal, may be accomplished in accord with accepted professional practice at the time such work is performed, without such permission. II. Terms and conditions of the temporary easement. A. Uses permitted under the temporary easement shall be: 1. Agriculture, including the tilling of soil, raising of crops, raising of livestock and poultry, and the maintenance and operation of dairies, mills, hatcheries, and/or other processing operations serving and required by the crops and/or livestock or poultry grown or raised upon the land described herein only.