168 Animal Husbandry 
The inlets may be so constructed as to meet two conditions: 
first, they must admit the fresh air near the ceiling, where the barn 
air is warm, in order that the fresh air may mingle with the warm- 
est air of the stable and raise the temperature before descending 
to the floor. In the second place, they must not permit the warm 
air to pass out instead of the cold fresh air to come in. This is 
accomplished by constructing the inlet flue so that it begins near 
the ground on the outside and ends near the ceiling on the inside. 
All that is necessary is to have the outer end of the flue several 
feet lower than the inner end. They should be placed on all four 
sides of the stable to take advantage of the wind. 
The outlets must be so constructed as to meet three conditions. 
First, the ventilators should reach nearly to the stable floor in 
order to remove the air from that point. This is desirable be- 
cause the refuse gases from the animals being heavier than the 
other air of the stable remain near the floor. The colder air is: 
at the floor, and it is desirable to remove this, particularly in the 
winter, in order that the warmer air at the ceiling may move down- 
ward. In the second place, these ventilators should be provided 
-with an opening near the ceiling for the removal of the warm air 
when the stable becomes too warm, particularly if the animals 
are to be kept in the stable most of the time. This open- 
ing must be provided with a door or slide to be closed or 
opened at will. In the third place, it is important that these 
ventilators be so constructed as to afford as little inconven- 
ience as possible, particularly when they extend through the 
hay loft, where they are sometimes in the way of the hay 
fork. The ventilating flue should be as large as convenient. 
The essentials of a good ventilating flue are similar to those 
of a good chimney. 
280. Window ventilation. — If it is not possible to install the 
King system in one of its many forms, the windows can be so ar- 
ranged as to form a fair system of ventilating the cow stable. 
To do this, hinge them at the bottom, allowing the top to open 
