590 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Mr. Englebright proposed, subsequently, the subject of "Ven- 

 tilation." 



VENTILATION. 



Col. Ruttan, of Canada, presented some of his views of ventila- 

 tion, and exhibited drawings in illustration. As to the necessity 

 for ventilation, all were agreed upon that. The question was 

 merely as to the modus operandi. Perhaps no man living had 

 expended so much time or money in experimenting upon ventila- 

 tion as he had. He had come to the conclusion that the prin- 

 ciples upon which ventilation is usually based are wrong ab initio. 

 The common method is to ventilate by mechanical, and not by 

 natural means ; and the mechanical means are a departure from 

 nature in this wise, that they are predicated upon the theory 

 that hot air naturally goes upward. That is not the fact. Air 

 has weight ; and heating it does not deprive it of its weight. 

 Hot air, therefore, naturally goes downward. It usually goes 

 upward, because we usually allow cold air to force it up. If we 

 provide means for taking the cold air from under it, hot air will 

 fall as certainly as lead. Warming a house by a true ventilating 

 process is the cheapest and most healthful mode. When a man's 

 feet are cold, he is cold all over ; and when his feet are warm he 

 is warm all over. The method which he would propose, founded 

 upon the true theory, was substantially this. The floor joists 

 are to be furred off about two inches, so that there shall be a 

 connected stratum of air between the floor and the ceiling below, 

 This air chamber communicates all around the edge of the room 

 with the room, and communicates also with the chimney or ven- 

 tilating flue. This stratum of air effectually prevents cold feet ; 

 for even should it sink to 40°, the feet being always covered with 

 leather and woolen, the natural heat of the body will prevent 

 them from becoming cold. The air is warmed in the hall, and 

 admitted into the room at the top. It is not necessary that it 

 fihould feel warm to the hand ; for air at 90° will feel cold to the 

 hand, and yet will warm a room sufficiently. The chimney acts 

 as a pump drawing out the cold air first from the space between 

 the floors and then from the lower part of the room, while the 

 warmer air in the upper part of the room falls to take its place, 

 and the heated air rushes in to fill the vacuum in the top of the 

 room. It is not necessary that rooms to be heated should be 

 immediately connected with the hall. He had warmed a room 

 where there were two intervening rooms which were not warmed. 



