at least 8 Inches down from top of pen, and in from the front far enough to be completely covered on each side by C.S. Animals like to watch each other on door and C.S. and get extra exercise by climbing up and down to do so. P.H. are not recommended near back of pen.
For those who do not wish to use rear inspection doors, optional back patterns are provided. Illus. 27a shows doorless back with vent strip. The lower part is solid board; then the ventilation strip and the top-tie (T.T.) strip. The hdw. cl. for the ventilation opening is installed so as to reach from top edge of top-tie down to at least 1 inch below top of back board (Bk. Bd.) as per Illus. 27b.
And, for any who may wish inspection back doors with individual ventilation openings, optional plan Illus. 36 shows construction of door, door tongue, corner posts and door fastener same as author's preferred pen choice Illus. 27. Corner posts are still to be installed in pen 1, Illus. 36. Illus. 37 and 38 show side view of construction, and Illus. 39 shows inside view of door. Individual ventilation openings are about 2 inches square.
The novice may think all of these suggestions con-
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