Counsel have stipulated that the only question to be determined on this appeal shall be “whether or not the duplicate of assessment-roll specified in the statute authorizing the improvement, should have had incorporated therein, by the auditor of the city and county of San Francisco, the certificate of the mayor,” appended to the original roll, certifying to its correctness.

The statute required the assessment-roll to be made up from the report of the commissioners, under the supervision of the mayor. It involved only a clerical duty; and “ when complete” the mayor was required to certify to its correctness and deliver it to the auditor, whose duty it was to make a duplicate of the roll, and deliver it to the collector. It appears in the record that the original roll was duly made and properly certified by the mayor, who delivered it to the auditor; but in making the duplicate for the collector the auditor omitted therefrom the certificate of the mayor. The court below held the omission to be immaterial, and we agree in that opinion.

Order and judgment affirmed. Bemittitur forthwith.

Mr. Justice McKinstry did not express an opinion.