72 VINEGAR, CIDER, AND FRUIT- WINES. 



wires projecting from the thermometer are connected by insulated 

 copper wires with a galvanic battery consisting of several ele- 

 ments, an ordinary door-bell being inserted in one part of the 

 conductor. If, now, in consequence of a continued increase in 

 the temperature, the mercury rises to the point of the platinum 

 wire at the figure 35, the circuit of the battery is closed at the 

 same time by the column of mercury, and the bell rings and 

 keeps ringing until the circuit is again opened by the mercury 

 falling below 35. 



The minimum electrical thermometer, used for indicating the 

 falling of the temperature below a certain degree, is so arranged 

 that one platinum wire is melted into the bulb of the ther- 

 mometer and the other in the tube at the point below which the 

 temperature is not to fall. As long as the mercury remains above 

 this point a battery, which changes a piece of iron to an electro- 

 magnet, whose anchor opens a second battery which is connected 

 with an electric bell, remains closed. .If the temperature falls 

 below the minimum, the circuit of the first battery is opened, and 

 the anchor of the electro-magnet falling down eifects the closing 

 of the second battery and sets the bell ringing. 



By placing such thermometers not only in the working room 

 but also in every generator, the control of the entire process 

 would be immensely facilitated, but at the present time these 

 useful and at the same time inexpensive instruments are but little 

 used in vinegar factories. 



In factories arranged according to the automatic system, the 

 alcoholic liquid is contained in vessels placed at such a level that 

 their contents can run directly into the generators. The alcoholic 

 liquid having to be correspondingly heated, adequate provision 

 must be made for heating the space in which the reservoirs are 

 placed. In order not to increase the height of the entire room, it 

 is recommended to place these vessels in the centre and give only 

 to this portion the required height. This has the further advan- 

 tage that the pumping up of the alcoholic liquid can be effected 

 by the use of a pump with a short rising-pipe, and the liquid can 

 be readily conducted from the reservoirs to the separate generators 

 by means of pipes. 



