At any time before the day fixed in said order of said Director for action thereon by said Director, any owner of, or person interested in, property liable to be assessed for the proposed work, or the duly authorized representative of such owner, or other person, in his behalf, may make written protest against the same or to the extent of the district to be assessed therefor, or both, or make any other protest with regard thereto. Such protest must be in writing, contain a description of the property in which each signer thereof is interested, sufficient to identify the same, set forth the nature of his interest therein, and delivered to the Department of Public Works of said City and County, the Secretary or a clerk of which shall endorse thereon the date of receipt thereof. No other protests or objections shall be considered by said Director, except oral protests made at the time at which said Director conducts the hearing mentioned in his said order. At the time set for hearing protests said Director may publicly postpone action on his said order from time to time, and all persons interested shall be deemed to have notice of such postponement and shall be governed thereby. The decision of said Director on all such protests shall be final and conclusive except in case of appeal to the Supervisors as in this Article hereinafter provided for.