Section 21
SEC. 21. At any time after five years from the granting and during the life of this franchise, the Government of the Philippine Islands may, by legislative enactment, upon such terms and conditions as to it may seem proper, require the grantee, his lessees, successors, or assigns to operate said tramway by electric or other power instead of by animal power. Should said grantee, his lessees, successors, or assigns decline, fail, or refuse to operate said tramway by the power required by the Government and in the manner and as directed by said Government, then the franchise granted by this Act shall be forfeited and all rights, privileges, and concessions granted by it shall end and terminate.