14 



FARMERS BULLETIN 603. 



This correction, added to the ai^proximate volume first found, gives 

 the true capacity of the vat as nearly as it is possible to calculate it, 

 though if the vat is unevenly constructed, no formula can be entirely 

 accurate. 



To illustrate the whole process of calculating the capacity of a vat, we will 

 suppose that a vat has been constructed after the plans and specifications of 

 the bureau elsewhere given. The measurements as taken, and as reduced to 

 decimals through the use of Table 3, are the following : 



Vat. 



Bottom length . . . 

 Bottom width . . . 

 Water-line length 

 Water-line width. 

 Depth 



Reduced to 

 decimals. 



Ft. 



12.0 

 1.5 



22.8 

 2.71 

 5.25 



In reducing to decimals, lengths need be carried only to the nearest tenth, 

 but width and depth should be carried out to hundredths. Throughout subse- 

 quent calculations an accuracy greater than 1 per cent is unnecessary, hence 

 decimal places should be cut off when multiplying so that each number multi- 

 plied, unless a whole number, shall contain not more than three figures. 



Applying the approximate rule: 



(1) (2) (3) (4) (5) 



22.8 2.71 17.4 36.7 193 



-H2.0 -f-1.50 X 2.11 X5.25 X_Ji 



2) 34. 8 2) 4. 21 36. 714 192. 675 1, 448 gallons, approximate capacity. 



17.4 



2.11 



Applying the correction : 



(1) (2) (3) (4) (5) 



22.8 2.71 5.4 3.29 17.3 



-12.0 -L50 X .61 X5.25 X 2^ 



2 ) 10. 8 2 ) 1.21 3. 294 17. 2725 43. 3 gallona, correction. 



5. 4 . 61 



The correct figure for the capacity of the vat is, therefore, 1,448+43=1,491 

 gallons. 



CONSTRUCTING A MEASURING ROD FOR THE VAT. 



In replenishing or strengthening dipping fluids it is frequont'ly 

 necessary to ascertain just how many gallons of fluid are contained 

 in a partially tilled vat. Taking the wator-linc measurements and 

 Uien calculating the contents is inconvenient and may sometimes 

 seriously delay dipping operations. Therefore it is desirable to con- 

 struct a measuring rod Avhich will give directly the number of gallons 

 of liquid in the vat at any time. Of course such a rod may be grad- 



