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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    any desired angle. In such cases and also in large sach windows, Cooper’s ventilators are very fre- quently used. They consist of a fig. 4. circular disc of glass with five oval apertures in it, which works on a pivot through its centre in front of and close to one of the panes of glass of a window. In this pane there are five similar holes pierced. It follows, there- fore, that when the disc is turned so that the holes in it are opposite Cooper s ventilator. those in the window, the air will get through them, and when it is turned so that the holes in it are oppo- site to the glass between the holes in the window pane, the air is prevented from entering. The chief advantage of this ventilator is that it has no parts made of metal and so does not get out of order or rust, and that is doubtless why it is so largely used, notwithstanding the fact that it does not give the entering air an upward direction. For small rooms and closets, windows swung on their centres, the upper half sloping inwards and the lower outwards, are very effective ventilators. The most suitable windows for large rooms, as assembly rooms, &a, in which great numbers of people congregate and where immense vo- lumes of air are required, are windows composed of several sashes which do not slide up and down, but slope forwards into the room when they are opened so as to form an opening of very large area, and at tire same time to give the entering air an upward direction. Air may also be admitted into a room, either
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