The petition shall be filed with the clerk of the legislative body of the municipal corporation. Within 10 days from the date of the filing of the petition, the clerk shall examine the petition and ascertain from the record of the registration of the electors of the city and county, or of the county in which the municipal corporation is situated, whether the petition is signed by the requisite number of qualified electors. Upon request of the clerk, the legislative body of the municipal corporation shall authorize him to employ persons specially to assist him in the work of examining the petition and shall provide for their compensation.