56 VINEGAR, CIDER, AND FRUIT-WINES. 



1 / 



ownjweight, thus obstructing the proper passage of the air^ It 

 has been sought to overcome this evil by placing several false 

 lath-bottoms in the generator, in order to divide the weight of 

 the filling into as many smaller weights as there are lath-bottoms. 

 Bnt^ this arrangement is also attended with inconveniences^ jt 

 being difficult to maintain a sufficiently strong draught^ofjairjLn^ 

 generators of such height. 



Some manufacturers hold that the production of very strong 

 vinegar containing 11 to 12 per cent, of acetic acid is only pos- 

 sible in very tall generators. This opinion is, however, un- 

 founded, the manufacture of very strong vinegar being just as 

 well or rather better effected in small generators than in those 20 

 feet or more high, which besides are very expensive. 



The manufacture of vinegar should be carried on in a room with 

 a low ceiling, since even with the best heating arrangement .the 

 temperature near the ceiling is always much higher than on the 

 floor. However, with the use of generators 20 feet high the 

 ceiling of the workroom must be at least 26 feet high, which 

 makes it impossible to maintain a uniform temperature, as the 

 difference between the upper and lower parts would frequently 

 amount to more than 25. 



The most suitable generators are very likely those with a height 

 not exceeding 10 feet, and a lower diameter of about 45 inches 

 f^uud an upper one of about 35 inches. A large diameter, to be 

 \ sure, contributes towards the maintenance of a uniform tempera- 

 \ ture in the generator, but it has the disadvantage of making it 

 1 difficult for the air to ascend uniformly through all parts of the 

 filling. This evil is sought to be overcome by placing in the 

 centre of the generator a tube open above and below and pro- 

 vided on the sides with holes. Such tube, however, does not 

 produce the intended favorable effect upon the draught of air in 

 the parts of the filling surrounding it, experience having shown 

 that the greater portion of the warm current of air ascending .in 

 the interior takes the nearest road to the tc-p, i. e., through the 

 tube, without passing sideways into the filling. Every generator 

 of suitable construction should be provided with a well-fitting 

 coyer. In this cover, Fig. 4, are bored in concentric circles holes 

 which are intended for draught apertures. If the draught of air 



