It shall be lawful for the Corporation of the Mayor, Councillors, and Burgesses of the City of Dunedin (hereinafter referred to as the Corporation), with the sanction and consent of the Governor of New Zealand, from time to time to lease by public auction at an upset rental to be fixed by the Corporation the Southern Market Reserve described in the Schedule, or any subdivisions of such reserve, for any term of years not exceeding 21 years, to take immediate effect in possession; and such leases (hereinafter called original leases) may, in addition to all such covenants, agreements, conditions, and provisions as are usual in such leases, at the option of the Corporation, contain provisions to the following effect—that is to say: That 3 months previous to the expiration of the respective terms of such original leases, 2 separate valuations shall be made by 3 indifferent persons, to be appointed in writing, as follows—one by the said Corporation, one by the lessee, his executors, administrators, or assigns, and the third by the 2 valuators, to be appointed as aforesaid: That the decision of such 3 valuators, or any 2 of them, shall be binding on all parties: That one of such valuations shall be made of all the buildings and improvements then on the land demised, and the other of the fair annual ground-rent of the said lands only, without any building or improvements, for a further term, not exceeding 21 years, from the expiration of the term granted by such original lease as aforesaid: That before the expiration of such original lease a new lease of the said land and premises for a further term not exceeding 21 years, containing similar covenants and provisions to those contained in such original lease as aforesaid, shall be put up to public auction at the upset price of the annual rent of the said land so valued as aforesaid, without buildings and improvements, subject to the payment by the purchaser of the value of the said buildings and improvements, so fixed by the valuators as aforesaid: That in the event of any person or persons other than the original lessee, his executors, administrators, or assigns, becoming entitled to such new lease, such person or persons shall forthwith pay in cash to the said Corporation for the benefit of the original lessee, his executors, administrators, or assigns, the amount of the value of the buildings and improvements so fixed as aforesaid: and, That the said Corporation shall pay over to the said original lessee, his executors, administrators, or assigns, the amount so paid to them by the purchaser of such new lease, without any deduction whatsoever, provided that the said original lessee, his executors, administrators, or assigns shall have previously paid all rent and other charges payable under the original lease.