288 WARMING AND VENTILATION. 



by i^lacing above each burner a little iron or copper pipe, f inch in 

 diameter, leading to the outside of the building. 



This simple and cheap method would suffice to render healthful a 

 large number of workshops where unfortunate tailors, seamstresses, and 

 others now live in an infected and unhealthful atmosphere. 



Since the combustion of gas produces a great amount of vapor, the 

 pipes which carry off the gaseous products should be short and direct to 

 avoid condensation. 



In addition to the disagreeable alteration of the condition of the air, 

 there is often an excessive elevation of temperature in shops placed 

 directly under the roof. We will mention further on the means for 

 remedying this by the inexpensive plan of sprinkling the roof. 



69. Glue and soa;pmanv factories. — In the preparation of these materials, 

 and of many others of the same kind, there arise disagreeableodors during 

 the boiling-operations. The most successful method adopted in England* 

 appears to be to cover the vat and to make two openings in the cover, 

 one of which admits the air, while the other, connected with the main 

 ventilating-chimney, or with the grate of the vat itself, draws down 

 the vapors and the air entering through the other hole, and carries 

 them outside the building. 



When there are many vats near each other, their ventilating-pipes are 

 usually connected with a single pipe leading to the chimney. 



If the odors to be carried off" are merely unpleasant and not danger- 

 ous, and are not i)roduced in great quantity, it will be sufficient to 

 make a sufficient number of openings in the ceiling, provided with short 

 sheet-iron i)ipes to produce the draft, and to make suitable provision 

 for the admission of fresh air. 



70. Manufactories of chloride of lime and similar substances giving off 

 acid vapors. — The doors of the room into which the workmen have to 

 enter are opened, and the rooms connected with a powerful ventilating- 

 chimney. The workmen do not enter until all the vapors have been 

 carried off by the fresh air introduced. 



71. Matcli factories. — The manufacture of matches, which produces 

 the most distressing complaints, and to which boards of health do not 

 j>ay sufficient attention, requires special details, into which it will be 

 well to enter. 



For this purpose, I quote from a very valuable report, made by M. 

 Freycinet, mining-engineer, the following description of the plans 

 adopted with success in a large establishment lately erected at Hemix- 

 eim near Antwerp, at which the builder, M. Genis, a talented Belgian 

 officer, has made a remarkable application of ventilation by a downcast 

 draught. 



Five separate buildings, used for storage of raw materials, for cover- 

 ing with sulphur, for preparing the phosphorus-tips, for dipping, for 

 drying and boxing, and for shipping constitute the manufactory proper. 

 * Extract from the reiiort of M. Freyciuet Sur la mhibriU des fabriqiits. 



