The expression “the special Act” used in this Act shall be construed to mean any Act which shall be hereafter passed, and which shall authorize the taking of lands for the undertaking to which the same relates, and with which this Act shall be so incorporated as aforesaid; and the word“prescribed” used in this Act, in reference to any matter herein stated, shall be construed to refer to such matter as the same shall be prescribed or provided for in the special Act, and the sentence in which such word shall occur shall be construed as if instead of the word “prescribed” the expression “prescribed for that purpose in the special Act” had been used; and the expression “the works,” or “the undertaking” shall mean the works or undertaking, of whatever nature, which shall by the special Act be authorized to be executed; and the expression “the promoters of the undertaking” shall mean the parties, whether company, undertakers, commissioners, trustees, corporations, or private persons by the special Act empowered to execute such works or undertaking.