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arrows, and hence will be washed clear of germs. On the increase of 

 pressure through fermentation activity the gas passes out at low pres- 

 sure by depressing the liquor in (5) until it gains exit, as indicated by 

 the arrows. This is ( the Noel air controller; but in the writer's work it 

 has proved entirely too complicated and too difficult to keep clean for 

 practical use. The principle of air control is undoubtedly correct, 

 but it is better accomplished by some of the following devices: 



The German "fermentation funnel" (fig. 16) is a simple and far 

 better device for controlling the air. This is a pottery or porcelain 

 device having a central tapering stem (a) with a basin-like vessel (5) 



FIG. 16. German earthenware ventilating funnel vertical section. 



around its upper end. The central stem (c) rises nearly to the height 

 of the outer rim, and is hollow. Over this hollow stem rests a remova- 

 ble cap (d), which extends to the bottom of the basin. The lower rim 

 of this cap where it rests under the liquid is notched for the passage 

 of gases, as indicated by the arrows. This device is inserted in the 

 bunghole of the cask, and by reason of the tapering stem can be made 

 to fit quite tightly; but it is always better to use some paraffin wax 

 around it. The control liquid is placed in the outer basin until it is 

 about one-third full; then the cap is put on and the device is ready for 

 operation. While this is an awkward looking device, it is the best 



