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BOARD OF AGRICULTURE. [Pub. Doc. 



location, use and action of ventilating tubes, on account of 

 its being necessary to make use of them under certain con- 

 ditions, although I never recommend their use, if a better 

 plan can be followed. My preference is for the Sheringham 

 valve system of inlets and outlets, or another system to 

 which I shall call your attention later. The Sheringham 



Fig 5 . — The Sheringham valve from the outside . 



valve, a patented device of English origin, is in principle a 

 window, either single or double, hinged at the bottom, 

 swinging in at the top, having, when open, the triangular 

 spaces between the edge of the sash and the edge of the 

 window casing closed with wood or a piece of sheet metal. 

 The action of the Sheringham valve is similar to that of a 

 partially open window, hinged at the bottom, swinging in- 



