The bonds, mentioned in section 12-1001, shall be payable in not to exceed twenty years from date. They shall bear interest not exceeding the rate of six percent per annum payable annually. Notice of the time and place of said election shall be given by publication three consecutive weeks prior thereto in some legal newspaper printed in and of general circulation in such municipality or, if no newspaper be printed in such municipality, in a newspaper of general circulation therein, and if there be no newspaper of general circulation in such municipality then by posting written notice in three conspicuous public places in said municipality with such posting to be done at the beginning of the third week prior to such election.