TURPENTINE. Hy. 
similar bottle is filled with the turpentine to be graded, and the color 
of the column of turpentine, looking through the length of the bottle, 
is compared with that of the bottles containing the standard samples. 
It is then given the grade which it equals in color, or, in case 
it falls in between two, it receives the grade of the lower or 
darker one. As previously stated, the color of turpentine is not per- 
manent, and it is therefore necessary to check frequently the stand- 
ardized samples against the No. 1 yellow glass by the laboratory 
method, adjusting them when any changes in color occur. 
PURITY AND PRESENCE OF WATER. 
An experienced naval stores inspector usually can tell whether a 
turpentine is pure or adulterated by his sense of smell, which becomes 
very acute through continued use in the lookout for suspicious-smell- 
ing material. Moreover, the presence of a foreign odor, such as that 
of kerosene, in an atmosphere in which the odor of pure turpentine 
is always pronounced, helps to identify any barrel containing mineral 
oil. The usual adulterants are light mineral oils. By placing a few 
drops of turpentine on the hands, rubbing them together, and bring- 
ing them up to the nose, the presence of mineral oil may be detected 
readily, if there is very much of it- When a little of the material is 
allowed to evaporate from the surface of the barrel, the presence of 
any adulterant having a lower rate of evaporation than turpentine 
can be determined by the oily or greasy appearance and the odor of 
the unevaporated portion. If the inspector has reason to suspect a 
shipment, he calls in the State supervising inspector, who makes a 
more detailed examination, including chemical tests when necessary. 
To determine the absence of water, a pemaen of turpentine is drawn, 
by means of a glass tube called a “thief,” from the bottom side as 
- the barrel lies. Simce water is heavier than turpentine, it may be 
removed from the barrel by means of the thief, if this simple test 
shows that it is present. 
VOLUME OF CONTENTS. 
First the capacity of the barrel of turpentine is determined by 
measuring with a gage rod the distance irom a point on either chine 
inside to the middle of the opposite side of the barrel, i. e., the middle 
of the inner side of the bunghole. A gage hook is used to indicate 
on the gage rod the center of the inner side of the hole. The gage 
rod is marked to show directly the capacity of the barrel in gallons, 
the average of the readings from both ends being taken as the capacity 
of the barrel. A symbol designating the capacity of the barrel is in- 
scribed or cut on a stave near the bunghole. 
Turpentine barrels hold from 50 to 53 gallons. All barrels offered 
for sale are packed to contain 1 gallon less than the full capacity, and 
this is called the ‘‘net gage” of the barrel. The surface of the tur- 
pentine in a barrel so filled is 14 inches down from the inner side of 
