s prevailing
within the drying room at all times of the day and night, and serves
not only as a means of keeping an accurate record of the operation of
the dry kiln, but as a valuable check upon the attendant in charge of
the drying process.

[Illustration: Fig. 98. The Registering Thermometer.]

[Illustration: Fig. 99. The Recording Steam-Pressure Gauge.]

The Registering Thermometer

In Figure 98 is shown the Registering Thermometer, which is a less
expensive instrument than that shown in Figure 97, but by its use the
maximum and minimum temperatures in the drying room during a given
period can be determined.

The Recording Steam Gauge

In Figure 99 is shown the Recording Steam Pressure Gauge, which is
used for accurately recording the steam pressures kept in the boilers.
This instrument may be mounted near the boilers, or may be located at
any distance necessary, giving a true and accurate record of the
fluctuations of the steam pressure that may take place within the
boilers, and is a check upon both the day and night boiler firemen.

The Troemroid Scalometer

In Figure 100 is shown the Troemroid Scalometer. This instrument is a
special scale of extreme accuracy, fitted with agate bearings with
screw adjustment for balancing. The beam is graduated from 0 to 2
ounces, divided into 100 parts, each division representing 1-50th of
an ounce; and by using the pointer attached to the beam weight, the
1-100th part of an ounce can be weighed.

[Illustration: Fig. 100. The Troemroid Scalometer.]

The percentage table No. II has a range from one half of 1 per cent to
30 per cent and is designed for use where extremely fine results are
needed, or where a very small amount of moisture is present. Table
No. III ranges from 30 per cent up to 90 per cent. These instruments
are in three models as described below.

MODEL A. (One cylinder) ranges from 1/2 of 1 per cent to 30
per cent and is to be used for testing moisture contents in
kiln-dried and air-dried lumber.

MODEL B. (Two cylinders) ranges from 1/2 of 1 per cent up to
90 per cent and is to be used for testing the moisture
contents of kiln-dried, air-dried, and green lumber.

MODEL C. (One cylinder) ranges from 30 per cent to 90 per
cent and is applicable to green lumber only.

=Test Samples.=--The green boards and all other boards inte