476 Transactions. — Miscellaneous . 



to waste up the chimney, rises as soon as it is sufficiently 

 warm, and circulates about the room, to be replaced by cooler 

 air from parts beyond the direct influence of the fire. By this 

 method, then, we have supplied the fire with air without 

 creating a draught, and have at the same time increased its 

 effectiveness as a dispenser of warmth. We may next proceed 

 to cut off its old and objectionable sources of supply by 

 fitting carpet-slips on the floor close up to the underside of the 

 doors or casements. Plate XLVIIL, fig. 6, shows a section of 

 the openings for admitting air to the fire. 



Having provided for the needs of the fire, we have only to 

 consider those of the gas and of the occupants. If we open a 

 window at the top we get a direct draught across the room or 

 down upon the heads of those sitting ; if we open one at the 

 bottom we get a draught across the body or neck. These 

 methods are therefore not admissible. We must arrange to 

 bring air in — (1) at a level at least higher than our heads 

 when we are sitting ; and (2) in such a direction as will insure 

 its passing upwards, and not downwards or across the room. 

 If we can do this we shall obtain a pure-air supply with the 

 minimum of risk to health or comfort. There are two ways 

 in which we may do it. The simpler plan in a new house is 

 to make the lower bar of each window-sash lin. deeper, 

 and then to build up the sill inside 2in. higher than usual. 

 This provides 3in. more than the customary overlap. It will 

 then be possible to lift the lower sash 3in. without leaving 

 a less than ordinary overlap, and therefore without making 

 any opening through which a direct draught could pass across 

 the room. But by this lift we have separated the dividing- 

 bars of the two sashes about l^in., and in such a way that 

 the air entering at this point must flow upwards, and cannot 

 create a draught downwards or across the room. Plate 

 XLVIIL, fig. 7, shows the section of a window-sash and sill so 

 constructed. 



In an old house a rough method may be adopted to effect 

 this object. Pit a piece of wood 3in. deep accurately to the 

 lower side of the window-sash and into the recess of the sill. 

 When ventilation is desired lift the sash, place the piece of 

 wood, and shut the sash down upon it. The inconveniences 

 of this plan are that the window 7 cannot be fastened without 

 removing the filling-piece, and that the latter has to be stow r ed 

 somewhere out of the way. 



The other way to admit air satisfactorily is to fit Tobin 

 tubes against the wall, and to supply them with air from the 

 space between two joists. Where it is possible to do so a 

 space should be selected which extends right through the 

 house, and each end should be provided with a grating. The 

 reason for this through passage is that if there is only one 



