148 ANNUAL OF SCIENTIFIC DISCOVERY. 



of heating, he says : " If we want our houses warmed and ventilated 

 we must supply a brisk and easy flowing body of air. The air should 

 pass out of the room at about sixty degrees temperature, and this 

 will make it necessary to take it from the ' air-warmer ' at ninety or 

 one hundred degrees in an ordinary winter's day, and with an ordi- 

 nary sized house, say forty feet square. In a very cold day, when the 

 air is liable to lose its heat much faster from the increased cool- 

 ing of the walls, the warm air should be brought in at a somewhat 

 higher temperature. There is a great advantage in being able to 

 bring in the warm air at that comparatively low temperature, as 

 thereby all danger of injuring it by overheating (as is often the case 

 with hot-air furnaces) is prevented." 



By the common mode of heating and ventilating buildings by 

 means of hot-air apparatuses, the cold air is taken in from below and 

 the warm air let out above. In churches, houses, and other buildings 

 the furnace or heater is placed in the basement, and the warm air 

 is conducted upward through openings in the floors. By this system., 

 the upper stratum of air in rooms is frequently too warm, while thfe 

 stratum near the floor is quite cold. As the feet of persons are most 

 liable to become cold, it is more necessary to have warm floors than 

 ceilings to obtain the greatest amount of comfort. By the Euttan 

 system this is secured in a peculiar manner, which may be called the 

 inverted siphon method. To give a general idea of it, suppose there 

 are three rooms placed above one another, and that the two upper 

 ones have floors laid with an open space of a few inches wide extend- 

 ing along their sides. A chimney or shaft extends from the base- 

 ment in the usual manner, but has only one opening inside, and that 

 is upon the lower room floor. This opening is covered with a slid- 

 ing door, and no air can get to the outside except by passing through 

 this door and up to the top of the chimney. Now, supposing warm 

 air is admitted from the heater by openings in the ceiling of the upper 

 room (the very reverse of the common method), no current will be 

 produced while the door of the chimney in the lower space or apart- 

 ment is shut; but whenever this is opened the warm air presses 

 downward, passing through the spaces along the sides of the floors, 

 then through the opening in the chimney, and up thence to the 

 atmosphere outside. By this ingenious method a natural draught is 

 produced ; the warm air is taken in from above, carried down through 

 the floors, and from thence outside, sweeping all the foul air with it. 

 It will be understood that warm fresh air is admitted constantly from 

 above. When air is heated in a room to 75.46 degrees above that of 

 the atmosphere outside, its pressure is increased two pounds on the 

 square inch. We may judge from this of the expansive force which 

 it possesses to produce a downward draught through rooms to the 

 opening in the shaft below, thence to escape into the atmosphere. 

 By this method of heating and ventilating, the stratum of air near 

 the floors of apartments is maintained at the same temperature as 

 that near the ceilings, and indeed the temperature in every part of 

 the room will be nearly uniform. In apartments constructed to carry 

 out this system, the floors, which are laid with an open space of a 

 few inches along the sides, have a perforated "base-board," which 

 may be of iron and of an ornamental character. 



