If the Director of Finance is not satisfied with the return and payment of taxes made by any person under the provisions of this chapter, he is hereby authorized and empowered to make an additional assessment of the tax due by such taxpayer, based upon the facts contained in the return or otherwise acquired. Promptly after the date of such additional assessment, the Director shall give or send by mail a notice thereof to such person, together with written notice of the time when and the place where such person may be heard on a petition for reassessment as hereinafter provided. (Ord. 1947-13. Passed 9-1-47.)