In cities governed hereby the commissioners may by ordinance acquire the necessary land and authorize and provide for the construction thereon of a building or buildings suitable for conventions, temporary or permanent exhibitions, entertainments, receptions, lectures, addresses, assemblages and other like purposes, and may lease all or any portion of such building or buildings and premises for any purpose which in their discretion they may deem advisable including the sale of merchandise and privileges, and may equip such building or buildings for the purposes herein mentioned, and may by ordinance provide from time to time for the issue of bonds in such amounts as may be necessary for such purposes.