290 WARMING AND VENTILATION. 



In front of each range of drying-chambers there is a small railroad, 

 extending from the melting-room to the warehouse. An iron car takes 

 the prepared composition, and carries it to the drying-chambers in suc- 

 cession. Before each door or station, an orifice, o' o', made in the floor, 

 exerts a powerful draught, which draws the vapors into the exterior lateral 

 tunnel. The dipping is quickly done, and the frames are immediately 

 placed in the drying-chambers, the iron doors of "which are carefidly 

 closed. 



The middle portion of the building is reserved for boxing. Under 

 the tables are also j)laced ventilatiug-openings, o" o". The filled boxes 

 are finally put in the car and carried to the warehouse. 



The main passage-ways c c and c' c' enter separately into the base of 

 the chimney, and are kept apart there by small vertical walls, in order 

 to prevent contrary currents and to allow them to be regulated at m ill. 



By means of these arrangements, all smell of phosphorus in the main 

 factory is prevented, and the men who work there are no longer exposed 

 to necrosis. By taking the additional precaution of having them fre- 

 quently visited by physicians, and of maintaining proper rotation in 

 the hands employed in the diflerent shops, they will be completely freed 

 from this terrible disease. 



MANUFACTORIES. 



72. In some manufactories, it is essential for the quality of the pro- 

 ducts that the internal temperature be not allowed to fall below a cer- 

 tain limit ; or, in other words, that the manufactory be heated even in 

 spring and fall, and that the windows be kept closed. From this it fol- 

 lows that the air, not being changed, becomes gradually saturated with 

 vapors and cutaneous emanations, and becomes at last unliealthful. 



The workmen being thus kept continually perspiring, although they 

 take off part of their clothing, go out afterward into the cold air, and 

 often contract serious affections of the respiratory organs. 



The conditions of the manufacture may be secured at the same time 

 with those of hygiene by a strong ventilation, which shall constantly 

 furnish fresh air of the necessary degree of temperature and even of 

 moisture while regularly carrying off the foul air. With this change of 

 air, a temperature of 75° or 77° will be found comfortable, and the work- 

 men no longer be continually perspiring in an atmosphere constantly 

 becoming more impure. 



The rules to be observed are the same as those mentioned before, and 

 a complete change three or four times an hour will usually be sufficient. 



The escape-steam from the engines is in such cases usually employed 

 for heating, and it may be so regulated as to give the desired tempera- 

 ture to the fresh air, and the smoke-stack of the steam-engine will, with- 

 out additional expense, maintain the draught required for carrying off the 

 foul air. 



In cases where the smoke-stack would be otherwise too small, the 



