13. Rooms in which suction gas plant is installed must be of such a height that all the plant and its connections can be easily reached for cleaning, &c., and be capable of such free ventilation as to render impossible an accumulation of gas. 14. These rooms must be separated from living rooms by a wall without any openings in it. Emanations also must be prevented as far as possible from entering into living or working rooms situated over the gas engine. 15. Erection of apparatus for generating and purifying suction gas in cellars shall only be allowed if specially effective ventilation is provided by natural or mechanical means. Other Regulations are those of the Prussian Ministerial Decree, dated June 20, 1904, as to the arrangement and management of suction gas premises. ACETYLENE GAS INSTALLATIONS (See also pp. 85-7) The following regulations for the protection of workers in acetylene gas installations are taken from the Prussian Ministerial Decree, dated 2 November, 1897: 1. Preparation and condensation of acetylene on the one hand, and liquefaction on the other, must be carried on in separate buildings. 2. If the pressure employed for condensation of the gas exceeds eight atmospheres, this work must take place in a room set apart for the purpose. 3. Rooms in which acetylene is prepared, condensed, or liquefied shall not be used as, nor be in direct connection with, living rooms. They must be well lighted and ventilated. 4. The carbide must be kept in closed watertight vessels, so as to ensure perfect dryness and only such quantities shall be taken out as are needed. The vessels must be kept in dry, light, well-ventilated rooms; cellar rooms may not be used for storage purposes. 5. Crushing of carbide must be done with the greatest possible avoidance of dust. Workers are to be provided with respirators and goggles. 6. Acetylene gasometers must be fitted up in the open air or in a well-ventilated room, separated from the gas generator. Every gas receiver must have a water gauge showing the pressure in the receiver. 7. Between the gasometer and receiver a gas purifier must be provided so as to remove impurities (phosphoretted hydrogen, arseniuretted hydrogen, carbon bisulphide, ammonia, &c.). 8. Condensation of acetylene gas at a pressure exceeding ten atmospheres shall only be done in combination with cooling. DISTRIBUTION AND USE OF POWER AND ILLUMINATING GAS