All gas furnished by any person engaged in the business of furnishing or supplying gas to any customer for heating, power, or illuminating purposes in the city shall be and is required to have a calorific value of not less than 1,000 British thermal units gross per cubic foot, as determined by a standard calorimeter measured at 60°F and under a barometric pressure of 30 inches of mercury.
(Prior Code, § 50.020) Penalty, see § 50.999