After the return of such assessment roll, the court shall make an order setting a time for the hearing thereof before the court, which day shall be at least twenty days after return of the roll. It shall be the duty of the commissioners to give notice of the assessment and of the day fixed by the court for the hearing thereof in the following manner:

(1) They shall at least twenty days prior to the date fixed for the hearing on the roll, mail to each owner of the property assessed, whose name and address is known to them, a notice substantially in the following form:

"Title of Cause. To  . . . .: Pursuant to an order of the superior court of the State of Washington, in and for the county of  . . . . . ., there will be a hearing in the above entitled cause on  . . . . . . at  . . . . . . upon the assessment roll prepared by the commissioners heretofore appointed by said court to assess the property specially benefited by the (here describe nature of improvement); and you are hereby required if you desire to make any objections to the assessment roll, to file your objections to the same before the date herein fixed for the hearing upon the roll, a description of your property and the amount assessed against it for the aforesaid improvement is as follows: (Description of property and amount assessed against it.)

(2) They shall cause at least twenty days' notice to be given by posting notice of the hearing on the assessment roll in at least three public places in the city, one of which shall be in the neighborhood of the proposed improvement, and by publishing the same at least for two successive weeks in the official newspaper of the city. The notice so required to be posted and published, may be substantially as follows:

"Title of Cause. Special assessment notice. Notice is hereby given to all persons interested, that an assessment roll has been filed in the above entitled cause providing for the assessment upon the property benefited of the cost of (here insert brief description of improvement) and that the roll has been set down for hearing on the  . . . . day of  . . . . at  . . . . . . The boundaries of the assessment district are substantially as follows: (here insert an approximate description of the assessment district). All persons desiring to object to the assessment roll are required to file their objections before the date fixed for the hearing upon the roll, and appear on the day fixed for hearing before said court.