The laws of health / by W.H. Corfield.

  • William Henry Corfield
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: The laws of health / by W.H. Corfield. Source: Wellcome Collection.

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    by which it could be allowed to pass directly from the upper part of the room into the chimney flue. Arnott Valve. An opening was made Fig. 8. through the wall near the ceiling into the chimney, and an iron box placed in it in which was a light metal valve capable of swinging towards the chimney flue, so as to allow a passage of air from the room into the chimney whenever the pressure of the air in the upper part of the room was greater than that in the chimney, but incapable of opening towards the room, so that whenever there was greater pressure in the chimney the valve was shut. Unless very well made and carefully padded, these valves are apt to make an irregular clicking noise, which is very dis- agreeable, and whenever they get out of order they admit blacks and air from the chimney flue. The noise is lessened by a modification of this valve known as ‘ Boyle’s Valve,’ in which, instead of there being one light metal valve, there are several small flaps of talc which are hung in front of holes in a metal plate, so that they can, like Arnott’s valve, open into the chimney, but not into the room. A much better plan than either of these is, however, to have a separate shaft running by the side of the chimney flue, and having an opening into each room near the ceiling. The air in this shaft gets heated and rises, and air is drawn into it from the upper part of the
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