It is further clearly understood that the cost of land purchased for the Railway, the salaries of the Managing Director, Chief Accountants, Chief Engineer, and the cost of their offices and staff shall not be included in the meaning of the terms "construction and equipment." The Contractors shall have the option of constructing on the same terms the proposed extension of the Railway to Lanchow in the Province of Kansu, or a Railway of similar mileage in some other part of China to be mutually agreed upon, and this option shall be for seven years from the commencement of construction. All other arrangements in connection with the construction and equipment of the Railway shall be settled in the Detailed Agreement referred to in Article 17. ARTICLE X All land that may be required along the whole course of the Railway within survey limits, and for the necessary sidings, stations, repairing shops and car sheds, to be provided for in accordance with the detailed plans, shall be acquired by the Corporation at the actual cost of the land, and shall be paid for out of the proceeds of the Loan. ARTICLE XI The Contractors shall hand over to the Corporation each section of the Railway, when completed, for operation in accordance with the provisions of the Detailed Agreement. ARTICLE XII The Contractors shall be appointed Trustees for the Bondholders and shall receive such remuneration as may be fixed in the Detailed Agreement. ARTICLE XIII The Government of the Republic of China, whenever necessary, will provide protection for the Railway while under construction or when in operation, and all the properties of the Railway as well as Chinese and foreigners employed thereon, are to enjoy protection from the local Officials. The Railway may maintain a force of Chinese Police with Chinese officers, their wages and maintenance to be wholly defrayed as part of the cost of the construction and maintenance of the Railway. In the event of the Railway requiring further protection by the military forces of the Government, the same shall be duly applied for by the Head Office and promptly afforded, it being understood that such military forces shall be maintained at the expense of the Government. ARTICLE XIV All materials of any kind that are required for the construction and working of the Railway, whether imported from abroad or from the Provinces to the scene of work, shall be exempted from Likin or other duties so long as such exemption remains in force in respect of other Chinese Railways. The Bonds of the Loan, together with their coupons and the income of the Railway shall be free from imposts of any kind by the Government of the Republic of China. ARTICLE XV With a view to encouraging Chinese industries, Chinese materials are to be preferred, provided price and quality are suitable. At equal rates and qualities, goods of British manufacture shall be given preference over other goods of foreign origin. ARTICLE XVI