312 BUILDINGS, SANITATION, AND DISEASES 
The ventilator is made by cutting the upper ends from two 
roof boards, opposite one another. Then 2’ by 2” pieces are 
nailed on top of the battens on each side of the opening, meeting 
at the top, and boards are nailed on top of these strips on eacn 
side of the roof. The upper ends of these boards meet at the 
top, and the lower ends come an inch or two past the lower sides 
of the opening. 
It is recommended to have a door at the back of the build- 
ing, similar to the one in front, for purposes of ventilation in 
hot weather; also a ‘small opening near the peak at the rear 
of the building, which could be covered with a slide, and used 
to assist ventilation under some circumstances. 
Owing to the fact that the runners are likely to decay, 
some prefer to have them not fastened to the building, so that 
they can be renewed conveniently. In the plan shown, the 
runners are fastened to the structure, but they could be attached 
by means of bolts, so that it would not be difficult to renew 
them. An application of tar would save them many years. 
The Shed Roof Pen.—(Wisconsin Bulletin 153.) The pen 
shown in the illustration is six feet four inches wide and eight 
feet long. In the rear, it is provided with a door, the same size 
as the lower front door, which is placed diagonally opposite, so 
that by opening all the doors, it makes a cool house in summer. 
By closing both lower doors and opening the upper front door 
for ventilation, it, makes a warm house for cool weather. The 
upper front door can be fitted with a wooden ratchet, by means 
of which it can be held in any position desired. 
To build the pen, construct the frame 9’ 0” long, by 6’ 4” 
wide, on seven 2” hy 4” joists six feet long. Nail two pieces of 
2” by 4” scantling across the ends of the joists, which will make 
the foundation for the floor %’ 0” by 6’ 4’. Beneath the 
frame are nailed three 2’”" by 4” pieces which serve as runners 
for moving the building. The pen illustrated here is six feet 
