78 VINEGAR, CIDER, AND FRUIT-WINES. 



this screw, the aperture can be closed more or less or entirely, 

 and thus the strength of the current of air regulated at will in 

 every generator. The prisms A of all the generators are con- 

 nected with each other by the conduit R, constructed of boards. 



Fig. 22. 



Fig. 23. 



Ventilating Apparatus according to Bersch. 



This conduit R is connected best in the centre between an 

 equally large number of generators with the condensing appa- 

 ratus, the chief feature of which is a worm similar to that used in 

 a still. Fig. 24 shows the apparatus in cross-section. 



In a sheet-iron vessel of the same height as the generator is 

 placed another vessel, so that there is a distance of about 5f 

 inches between the walls. From a reservoir situated at a higher 

 level cold water runs into the apparatus through the pipe K, and 

 off through the short pipe W. In the space between the walls of 

 the two vessels lies a tin coil with very thin walls and a diameter 

 of at least 2J inches. On top this tin coil is connected with the 

 wooden tube R (Fig. 23) and below with the iron pipe R r which 

 leads to the ventilating apparatus. C is a glass tube about 16 

 inches long and J to f inch in diameter, which reaches nearly to 

 the bottom of the flask half filled with water. 



The ventilating apparatus consists of an ordinary Meidinger 

 self-regulating stove, but its jacket is closed below so that air can 

 only pass in between the heating cylinder and the jacket through 

 the pipe R v coming from the condensing apparatus. 



