Each and every bond issued for any such improvement shall be signed by the chair of the county legislative authority and the county auditor, sealed with the corporate seal of the county, and attested by the county clerk. The bonds issued for each local improvement district shall be in the aggregate for such an amount as authorized by the resolution of the county legislative authority with reference to such river, lake, canal or harbor improvement, and each issue of such bonds shall be numbered consecutively, beginning with number 1.