TURPENTINE. iT: 
In this example the depth of the dome pocket, as determined by the 
method just given,.is 6.8 inches, and the measured outage is 6 inches. 
The ratio of 6 to 6.8 is slightly greater than $, and accordingly the 
dome pockets are practically empty. Therefore, the total dome pocket 
capacity (10 gallons) must be added to the outage volume as calcu- 
lated for the tank proper. The total outage on this car, then, is the 
sum of 285.2+1.5+10 gallons, or 296.7 gallons. 
BASIS OF SALE. 
In this country turpentine is sold almost exclusively by the United 
States gallon, which measures 231 cubic inches; in England it is sold 
by the hundredweight (112 pounds); and on the continent of Europe 
by the kilogram (2.2046 pounds), commonly known as the ‘‘kilo.” 
Turpentine shipped in tank cars is sometimes weighed and the 
gallonage calculated from the weight. In this case the commercial 
practice is to consider 7 pounds as a gallon. In most cases, however, 
this is incorrect, as only the very lightest turpentines at temperatures 
above 100° F. weigh as little as 7 pounds per gallon, as shown in 
Table 5. The exact weight per gallon of any lot of turpentine at 
various temperatures can be found from Table 5. 
If turpentine is purchased by volume, it should be paid for on the 
basis of the volume at the standard temperature of 60° F. This may 
be determined as shown in example 2, page 48. If purchased by 
weight, it should be paid for at so much per pound or per 100 pounds. 
In weighing a car of turpentine the stenciled weight of the empty 
_ car is usually accepted as correct. If a reliable railroad scale (known 
to be correct) is available, however, it is safer to weigh the car before 
and after loading, thus obtaining the true weight of the turpentine, 
as any error in the scale reading would appear in both the loaded and 
empty weight of the car. The weight of a railroad car as given in 
bills of lading is frequently incorrect by as much as 200 pounds, 
due to inaccuracy of scales, carelessness in weighing, or weighing cars 
which are wet or coupled to other cars not on the scales. 
Obviously, then, the purchase of turpentine in tank carlots, at so 
much per gallon, based on a preassumed weight per gallon (com- 
monly 7 or 7.2 pounds per gallon) introduces possibilities of two 
important errors in judging the quantity of the contents, one due to 
Inaccurate weighing on railroad scales, the other to the difference 
between the actual weight per gallon of the particular turpentine 
and the assumed weight. As a matter of fact, a pure turpentine 
which weighs as little as 7 pounds per gallon, equivalent to a specific 
gravity of approximately 0.841 at 15.5°/15.5° C., 1s never obtained 
from present sources of American turpentine. 
