AN ORDINANCE REQUIRING ANY PERSON, FIRM, CO-PARTNERSHIP, CORPORATION, OR ASSOCIATION IN THE CITY OF MANILA TO FURNISH TO THE OFFICE OF THE CITY ENGINEER OR THE FIRE DEPARTMENT A LIST OF PROFESSIONAL MECHANICAL ENGINEERS, OR MECHANICAL PLANT ENGINEERS, OR JUNIOR MECHANICAL ENGINEERS, OR CERTIFIED PLANT MECHANICS AND/OR A LIST OF PROFESSIONAL ELECTRICAL ENGINEERS, ASSOCIATE ELECTRICAL ENGINEERS, ASSISTANT ELECTRICAL ENGINEERS OR MASTER ELECTRICIANS, HOLDING VALID CERTIFICATES OF REGISTRATION ISSUED BY THE BOARD OF MECHANICAL OR ELECTRICAL ENGINEERING EXAMINERS EMPLOYED BY THEM, AND FOR OTHER PURPOSES.