THE CONTROL OF THE FACTORY. 



observations gives the data to calculate its weight. Tanks of symmetrical 

 pattern can be readily gauged, and if there is reason to suspect their sym- 

 metry they must be calibrated by filling into them water from some convenient 

 measure such as a 100 gallon cask. 



In some factories conveniences for measuring the cold juice are absent and 

 it is only possible to measure the hot juice ; allowance must then be made for 

 expansion and for evaporation. Taking the volume of a 15 per cent, sugar 

 solution at 84F. as unity, the volume at 180 F. is 1-0216, at 185 F. is 

 1-0285, at 190 F, is 1-0303, at 195F. is 1-0327, at 200 F. is 1-0345, and at 

 205 F. is T0377; the expansion of the juice is so great compared with the 

 expansion of the receiving tanks and so many other sources of error are 

 introduced that change in volume of these may be neglected. 



The weight of water evaporated in heating is given by the following 



7? 7? 



formula : Weight of water evaporated per unit of evaporated juice = 2 - 



-"i 

 where l and J9 2 are the degrees Brix of the raw and heated juice 



respectively. 



Howe Juice Scales. In the Howe scales 

 two tanks are arranged on a weigh bridge; when 

 one tank has received so much juice as to 

 approach a pre-arranged limit, the flow to that 

 tank is cut off ; balance is made by an attendant 

 adjusting a sliding weight ; pulling a lever 

 stamps on a card the net weight contained; the 

 tank then discharges its contents while the 

 second one is filling. 



Baldwin* t Juice Weigher. This appliance 

 for automatically weighing the juice is illus- 

 trated in Fig. 267 ; the drum c is divided into 

 compartments, of which one is filling while 



another is emptying ; this drum is suspended from one end of a steel yard ; 

 juice flows into one compartment from the tank a and when balance between 

 the drum and its contents and the counterpoise w is obtained, the flow of juice 

 is automatically turned into the other compartment; as this compartment fills, 

 the drum soon revolves and discharges the juice from the weighed compartment ; 

 when balance is nearly obtained, the flow of juice from a is moderated 

 automatically; at each weighing a small sample of juice is diverted into 

 a bottle. 



Hedemann Weigher. This appliance is constructed by the Honolulu Iron- 

 works ; it consists (Fig. 268) of a container a a divided into two compartments 

 by a partition ; this container is mounted on a knife edge ; arranged along its 



493 



FIG. 267 



