29. At any time after the formation of any such company, if the directors are of opinion that it is desirable to alter, improve or extend the said work, or that the original capital subscribed will not be sufficient to complete the work contemplated, the said directors, under a resolution to be passed by them for that purpose, may:(1) Issue debentures, for sums not less than $100 each, signed by the president and countersigned by the treasurer of the company, and not exceeding in the whole 1/4 of the paid up capital, or
(2) Borrow upon security of the company, by privilege upon the works and tolls thereof, a sufficient sum to complete the same, or
(3) Authorize the subscription for such number of additional shares as may be named in their resolution, a copy whereof, under the hand of the president and seal of the company, shall be engrossed at the head of the subscription list to be opened for subscribers to the additional shares so authorized.