to or out of the boiler. See that the blow-off is tight,
that there is no drip from gage cocks, and that the feed-line
connections are tight, so that all the water fed to the boiler will
represent accurately the amount evaporated during the test.

If a meter is used instead of the three-barrel method, make
absolutely sure that the meter is correct, as the accuracy of the
test depends on the accuracy with which the water measurements are
made. _After a meter is installed, test it to see that it operates
correctly under the plant conditions._

The water level in the boiler should be the same at the end of the
test as at the beginning. As the time for stopping the test draws
near, therefore, try to bring the conditions the same as at the
start. Do not, however, run the feed pump rapidly in the last few
minutes for the test in order to obtain the same water level. If
there is a slight difference in level, calculate the weight of
water it represents and make the necessary correction to the total
weight of water fed.

TEMPERATURE OF FEED WATER.

Every plant should have a thermometer on the feed line, so as to
find the temperature of the feed water. Preferably, this
thermometer should be of the recording type. If such a form of
thermometer is used during the test, it is unnecessary to take the
feed temperature at stated intervals, as the record will show the
varying temperatures, and so the average feed temperature during
the test can easily be found.

If there is no thermometer in the feed line, take the feed-water
temperature by means of a thermometer hung in barrel 3 (figure 2)
by a hook over the edge of the barrel. Read this thermometer every
half hour during the test if the feed-water temperature is fairly
uniform; but if it varies considerably, read the thermometer every
15 minutes. The object is to obtain the average feed-water
temperature during the test period. Therefore, mark down the
temperatures as read at the stated intervals. At the close of the
test add the readings and divide their sum by the number of
readings and you will have the average temperature of the feed
water.

STEAM PRESSURE.

Every boiler is fitted with a steam gage by which the pressure is
indicated. It is important that the pressure gage be accurate. What
is wanted in a test is the average pressure of the steam in the
boiler, therefore, observe the pressure at regular intervals, just
as with the feed-water temperature, and mark dow