ARSENICAL CATTLE DIPS. 



13 



Table 3. — Equivalents of linear inches and decimals of 1 foot. 



There is an old, much-used rule for obtaining the capacity of a 

 dipping vat which, though somewhat inaccurate, possesses the marked 

 advantages of being easily grasped and, therefore, of not being liable 

 to error in its application and of being readily worked out inde- 

 pendently if partially forgotten. This approximate rule for present 

 purposes may be stated as follows: Multiply the average length hy 

 the average width^ the product hy the depth., and this pn'oduct hy 1\.^ 

 The average length is of course obtained by adding the bottom length 

 to the water-line length and dividing the sum by 2; the average 

 width is obtained in the same manner. 



The rule may be thus expressed as a formula : 



top length + bottom length top width + bottom width 



Q X Q X deptn X * y ■ — 



approximate gallons capacity. 



As previously noted, the results given by this rule or formula are 

 not quite accurate. In fact, it does not account for the upper corners 

 of the vat at the exit incline, and so the vat really holds somewhat 

 more dip than thus calculated. The volume of this additional por- 

 tion of the vat may be easily calculated after the following correction 

 rule : Multiply half the difference of the lengths hy half the difference 

 of the widths, the product hy the depth, and this product hy 2^.* 



Expressed as a formula the correction becomes : 



bottom width , . 



— — X depth X 2^ = 



top length — bottom length top width 



2 



additional gallons capacity. 



'^ The precise figure is 7.48 ; that is, the number of gallons In one cubic foot. 

 = That is, by one-third of 71. Mathematically the correct order is to multiply by one- 

 third the depth, then by 7J. Practically, of course, the result is the same. 



