THE DAIRY BARN I2/ 



upon the fact that warm air rises and cold air falls. 

 The ventilation in the barn described was arranged 

 with this law as its basis, and has worked satis- 

 factorialy. The construction is as follows: 



The driveway in the second story crosses the barn 

 at right angles with the cow stables, and is entered 

 by a short bridge and grade at the side of the barn. 

 On each side of this driveway, about three feet above 

 it, separating it from the bays in either end of the 

 barn, are the " breast girts." Next to the side 

 of the barn, under the girts, a space is partitioned 

 off, allowing an opening about three feet square from 

 the side of the driveway to the stable beneath. 

 There are three of these openings. In the fourth 

 corner is the stairway, which makes the fourth 

 ventilator. Slides are placed before the three open- 

 ings, closing them wholly or partly, as needed. The 

 stairway is closed by a trap door, operated by 

 pulley and weights. The cold air being heavier 

 than the surrounding atmosphere, as it comes 

 through the opening, drops to the floor. As it is 

 breathed by the cattle and warmed by their bodies, 

 it courses toward the center of the barn and toward 

 the ceiling, thence to the openings and out. At each 

 of these openings will be found the two currents, 

 the cold air going in and the warm coming out. 

 These currents have been proved experimentally 

 with smoke. The moisture formed by the breathing 

 in the stables below often condenses in cold weather 

 in the barn above, and forms considerable quantities 

 of ice ; another evidence of the circulation. At the 

 " peak " of the barn is a ventilator 8x6x5 feet. 

 Its sides are composed of slats, which admit the 



