No. 4.] 



STABLE VENTILATION. 



123 



ward at the top (Fig. 5). The wind striking against the 

 oblique window surface is deflected from its straight course, 

 thrown into the upper part of the building, and, being heavier 

 than the air already in the building, gradually finds its way 

 to the floor, where it comes in contact with the animals. 

 The closing of the triangular spaces on the sides prevents 

 downward draughts directly upon occupants of the stable. 

 Sheringham valves are found in the market with sash and 

 frame made of cast or malleable iron. These are too expen- 

 sive for use except in limited numbers. 



Fio. 6. — Cross-section of a Sheringham valve or window. 



A modification of it, which includes all its desirable feat- 

 ures, h an ordinary window, hinged at the bottom, swinging 

 in at the top with the side openings closed. All the material 

 required to convert a common sliding sash into a Sheringham 

 valve is a seven-eighths-inch board, eight to ten inches wide, 

 as long as the sash, planed at both sides ; two or three strips 

 of one-half-inch material, one and one-fourth inches wide; a 

 pair of butts and one old-fashioned spring barrel bolt. The 

 eight-inch board is split lengthwise between diagonally 

 opposite corners. These pieces are nailed to the inside edges 

 of the casing. The narrow strips of material are nailed to 



