natural to turn to some analytical method of
detecting the amount of saline and foreign matter leaking into the
condensed steam. Unless, however, only approximate results are required,
such methods are not advocated. There are many reasons why they cannot
be relied upon for accurate results, among these being the variation in
the percentage of saline matter in the sea-water, the varying
temperature of the condenser tubes through which the water flows, and
the uncertainty of such analysis, especially where the percentage
leakage of pure saline matter is comparatively small.

The Vacuum Test

Having convinced himself of the satisfactory conduct of the condenser
under the foregoing simple preparatory water tests, the tester may
safely pass to considerations of vacuum. There exists a good
old-fashioned method of discovering the points of leakage in a vacuum
chamber, namely, that of applying the flame of a candle to all seams and
other vulnerable spots, which in the location of big leaks is extremely
valuable. Assuming that the turbine joints and glands have been found
capable of preventing any inleak of air, with only a small absolute
pressure of steam or air inside it, and, further, an extremely important
condition, with the turbine casing at high and low temperatures,
separately, a vacuum test can be conducted on the condenser alone.

This test consists of three operations. In the first place a high vacuum
is obtained by means of the air pump, upon the attainment of which
communication with everything else is closed, and results noted. The
second operation consists in repeating the above with the water
circulating through the condenser tubes, the results in this case also
being carefully tabulated. Before conducting the third test, the
condensers must be thoroughly warmed throughout, by running the turbine
for a short time if necessary, and after closing communication with
everything, allowing the vacuum to slowly fall.

A careful consideration and comparison of the foregoing tests will
reveal the capabilities of the condenser in the aspect in which it is
being considered, and will suggest where necessary the desirable steps
to be taken.

VI. TESTING A STEAM TURBINE[4]

[4] Contributed to _Power_ by Thomas Franklin.

Special Auxiliary Plant for Consumption Test

There are one or two points of importance in the conduct of a test on a
turbine and these will be briefly touched upon. Fig. 70 illustrates th