Section 23
SEC. 23. Upon such terms and conditions as may be agreed upon, and at any time during the existence of this franchise, the grantee, his lessees, successors, or assigns may construct, maintain, and operate such additional sidetracks, double tracks, loops, switches, and passing places as may be deemed useful for the convenient and advantageous operation of said tramway, the consent of the municipalities concerned and of the provincial board of Tarlac having been first obtained: Provided, however, That the construction of-such additions to the original tramway shall not be entered upon until the grantee shall have filed with the "Director of Public Works, in duplicate, a map or plan of such proposed addition, accompanied by the explanatory statement, and shall have had returned to Mm a copy of said map with the approval of the said Director of Public Works. All such additions, when completed, shall become a part of tiie said tramway, and shall be held, maintained, and operated c upon the same conditions as those which govern and control the rest of said tramway.