use and gives the percentage of water direct without multiplying by 
two, which must be done in employing the one commonly used. 
Usually a small quantity of oil is carried over into the measuring 
cylinder and collects on the surface of the water, so that the readings 
should be made at the bottom of the meniscus between the oil and 
the water, as shown in figure 4. After the test has been made the 
graduate should be 
emptied and wiped 
dry. A cleaner- can 
be made by doubling 
and twisting a wire 
which has a fair de- 
gree of stiffness and 
wrapping absorbent 
cotton or waste around 
the end above the 
hooks. The ends of 
the wire should be 
turned around in a half 
circle, so as to make a 
convenient hook to 
catch the cotton or 
waste, as illustrated in 
figure 5. 
OIL USED IN MAKING 
THE TEST. 
The oil to be used 
should be the same as 
that specified in Circu- 
lar No. 72 of the Bu- 
reau of Plant Industry, 
in which it is described 
in part as follows : 
In making tests a good 
grade of mineral engine oil 
should be used. The oil 
must be free from water, 
should have a flashing point 
to 401° F.), and preferably a 
After the tests are com- 
Fig. 3.— Sectional view of the Brown-Duvel moisture tester, showing 
the various parts connected for use. A , Distillation flask in posi- 
tion, three-eighths of an inch above the wire gauze ; B, distillation 
flask in the wooden rack used only during the rilling. 
in open cup of approximately 200° to 205° C. (392 
viscosity between 10 and 15 (Engler) at 20° C. (68° F.) 
pleted and while the oil is still hot, empty the contents of the flasks into a strainer 
to recover the oil, which can be used repeatedly. A funnel strainer fitted to the 
mouth of a 3 or 4 gallon milk can is serviceable and inexpensive. 
The funnel strainer mentioned is shown" in figure 6. There should 
be a small quantity of absorbent cotton placed in the bottom of this 
strainer, so that only the oil can collect in the can beneath. 
