Cowl (oast)

A cowl is a device used on a kiln to keep the weather out of and to induce a flow of air through the kiln. They are normally associated with oasts but can also be found on breweries (Letheringsett, Norfolk), maltings (Ware, Hertfordshire; Hadlow, Kent) and watermills (East Linton, East Lothian).

This section deals with the traditional cowls found on oasts, with particular reference to the South East. From the outside, a cowl appears to just sit on the roof of the kiln. High in the roof of the kiln is a beam spanning the centre, called the sprattle beam, this carries a bearing which the pintle on the bottom of the centre post sits in. At the top of the kiln, the centre post passes through a two or three armed top stay iron. At the top of the centre post is carried the back board which carries an elm curb ring at the bottom, and one or two curb rings higher up on all except the smallest of cowls. A tie beam could also be carried, either at each curb level, or just the bottom curb level, spanning the width of the cowl. The top of the backboard carries a shaped top plate to which the weatherboards were affixed. The whole is covered in tapered weatherboards, widest at the bottom and narrowest at the top. Slotted through the centre post and attached to the back board is the distinctive finger which sometimes carried a motif. The finger assisted the turning of the cowl in light winds. Weatherboards would be attached to the cowl with nails made from copper. Cowls were usually painted white, although some were cream. The cowl is constructed so that when looking down vertically on a kiln, it covers the whole of the opening. It also covers some ⅔ to ¾ of the circumference of the kiln opening, the remaining section being open to allow air to vent from the kiln. An illustration of a cowl and the cross-section of a kiln can be seen here.

...
Wikipedia