The Governor may, by notice in the Gazette, set apart for the society at Christchurch registered under The Companies Act 1882, as the Canterbury Society of Arts, all that parcel of land with the buildings thereon vested in Her Majesty the Queen, situate in the City of Christchurch, and described in the Schedule hereto, upon trust as a site for the extension of the present building erected by the said society on the adjoining land, and to be used as a public art gallery and for the promotion of the fine arts, subject to such terms and conditions as are hereinafter mentioned, and may grant the said land to the said society accordingly upon condition that if the said land shall not be used for the purpose aforesaid within five years from the date of such grant such land shall revert to the Crown, and upon such other terms and conditions to be mentioned in the grant as the Governor may think necessary for securing that the said land shall be used only for the purposes aforesaid.