Obtain an influx of fresh air without drafts and without too great cooling of the air, and you have solved the problem of ventilation. To prevent an undue fall of temperature, there must be, in addition to a fresh-air supply, a continuous heat supply, and this exists in the fowls themselves. This we must plan to conserve. Admitting the fabric-covered window—now so universally used—to be the best solution of how to admit fresh air with the least loss of heat, the accompaniment of this is perfect tightness of the windowless sides.

As far as materials are concerned, wood, brick, cement blocks, or stone, are equally satisfactory if their requirements are understood, and they are used to suit conditions. Some poultrymen object to brick or stone, claiming that they are damp, yet we know that stone does not create moisture. Of course, masonry being a better conductor of heat than wood, moisture already in the air will condense upon stone, concrete, etc., when it will not be evident on wood. The moisture-laden air, which is cold and unhealthy for the fowls, must be due to a damp floor, poor ventilation, or some such reason. The fact that a certain concrete or stone wall is dry would prove that conditions were right, while the wooden wall would show warning signs only in extreme dampness.

In localities where stone abounds, the entire building may be constructed of stone, giving ample window room.

All buildings which are plastered or cemented in any part of their construction should be allowed to dry thoroughly before the flock moves in.

As an important aid to uniformity of temperature in winter, the wall space filled with confined air is important. The cement blocks and hollow building tile provide for this to a certain extent. A double board wall may give this result if carefully constructed. By placing sheathing paper under the weather boards, and also under the ceiling boards, a very satisfactory wall is possible.

A warm wall is made by combining brick and boards—using weather boards outside, brick within, and plaster, or ceiling boards, on the inner side.

A single board wall can be made comfortable as winter quarters by covering the outside with roofing paper and having it painted black. These black-painted hen houses and coops are too warm in summer, however.

The inside walls of the hen house should be smooth enough to be kept clean. A good wood-filler in the crevices prevents lice and mites from lodging there, but if, when whitewashing the walls, care is taken to work the lime into the crevices with the brush, and this work is done often enough, say four times a year, such pests would be kept down.

Make it a rule to have the windows on the light, sunny side of the building, facing south or southeast, but have none on the other three sides.

Windows really ought to be of such a size and position that the sunlight can reach every part of the floor space during some part of the day. Though we all believe in the benefit of sunlight, we do not always realize how important a part it plays in the care of poultry. When we consider that vermin and disease thrive in its absence, and that remedial measures are more or less troublesome and expensive, we will work into our building schemes every possible inlet for sunlight.

The windows should occupy a large part of the front wall area—one-third of it, at least, and be evenly distributed over the upper part of the surface. Movable window sash or curtain frames are imperative.

The position of the ventilating arrangement depends upon the position of the fowls at night. It is a strange fact that human beings, animals, and poultry can better stand a current of air coming directly toward the front of the head than from the rear or sides; hence I would place the roosts so that the fowls face the window and get the fresh air on a level with the nostrils rather than from above or below. Thus they are fortified against a drop in temperature. For example, where the roosts are to be two feet above the floor, I would have the windows about twenty inches from the floor, provided the roof is correspondingly low. With the roosts three or four feet above the floor, the window should be from thirty-two to forty-four inches above the floor, etc. I think it is safe to have the windows not higher than eight or twelve inches below the eaves, and six inches from the sides of the building.

Despite the fact that some poultrymen have discarded glass, I cannot rule it out altogether. It certainly has its uses on cold wintry days when the heat of the sun's rays is wanted without the chill wintry air. I believe these glass windows should be covered at night, and that the fabric curtain is therefore the most sensible mode of night ventilation. Burlap, sacking, or coarse muslin may be used to cover the window frames. Burlap is the most substantial. In tacking it to the frame, tacks with tin discs beneath the head (like those with roofing nails) may be used, or a thin light strip of wood may bind the burlap to the frame, and through it the tacks are driven.

Wherever glass is used, some protection of poultry wire is necessary to prevent its being broken.