16. Abandonment of Contract. If the work to be done under the contract shall be abandoned by the Contractor, or if at any time the Engineer shall be of the opinion, and shall so certify, in writing, to the Commission, that the performance of the contract is unnecessarily or unreasonably delayed, or that the Contractor is willfully violating any of the conditions of the specifications, or is executing the same in bad faith, or not in accordance with the terms thereof, or if the work be not fully completed within the time named in the contract for its completion, the Commission may notify the Contractor to discontinue all work thereunder, or any part thereof, by a written notice served upon the Contractor, as herein provided; and thereupon the Contractor shall discontinue the work, or such part thereof, and the Commission shall thereupon have the power to contract for the completion of said work in the manner prescribed by law, or to procure and furnish all necessary materials, animals, machinery, tools and appliances, and to place such and so many persons as it may deem advisable to work at and complete the work described in the specifications, or such part thereof, and to charge the entire cost and expense thereof to the Contractor. And for such completion of the work or any part thereof, the Commission may for itself or its contractors, take possession of and use or cause to be used any or all such materials, animals, machinery, tools and implements of every description as may be found on the line of the said work. The cost and expense so charged shall be deducted from, and paid by the City out of such moneys as may be due or may become due to the Contractor, under and by virtue of the contract. In case such expense shall exceed the amount which would have been payable under the contract, if the same had been completed by the Contractor, he shall pay the amount of such excess to the City. When any particular part of the work is being carried on by the Commission, by contract or otherwise, under the provisions of this clause of the contract, the Contractor shall continue the remainder of the work in conformity with the terms of his contract, and in such manner as in no wise to hinder or interfere with the persons or workmen employed by the Commission by contract or otherwise as above provided, to do any part of the work or to complete the same under the provisions hereof.