1. After the expiration of thirty days from the date of said order, the commissioners of such district shall issue special assessment bonds of the district as follows: If no election to pay in full the tax so ordered shall have been filed with the county clerk, as herein provided, said bonds shall be for an amount not exceeding ninety percent of the total amount of the tax so ordered; and, if such an election or elections shall have been so filed, then said bonds shall be for an amount not exceeding ninety percent of the total amount of the tax so ordered, after deducting the amount assessed against any and all tracts, the owners of which shall have filed an election to pay in one installment as herein provided, said bonds to be in denominations of not less than one hundred dollars, having some convenient date, and bearing interest from such date at a rate not to exceed six percent per annum. The interest of such bonds shall be payable on the first day of each April and October after said date, until all of such bonds are paid.

2. Said bonds shall be payable in the same number of installments, which need not be equal, as the special tax so ordered; one of which shall become due and payable on the first day of April after each installment of such tax becomes payable. Both principal and interest shall be payable at some convenient banking house or trust company’s office to be named in said bonds.

3. Said bonds shall be signed by the president of the road district and attested by the county clerk, who shall, before the delivery thereof, register the same in a suitable book for that purpose. After such bonds are so registered, they shall be presented to the state auditor for registration, who shall register the same as bonds mentioned in sections 108.240 to 108.300 are required by law to be registered, and the provisions of said sections shall be applicable to bonds issued pursuant to sections 233.170 to 233.315, the same as to bonds mentioned in said sections.

4. Such bonds, after being so registered by the state auditor, shall be deposited with the county treasurer in whose custody they shall remain until disposed of as authorized by sections 233.170 to 233.315, and such bonds after being so registered by the state auditor, shall be eligible as good and lawful securities for any and all purposes that bonds issued under the provisions of sections 242.010 to 242.690 and sections 243.010 to 243.540 are made so eligible for by sections 108.240 to 108.300 and county commission of this state may invest school funds or other trust funds that may be under their control, in said bonds at their par value.