inclined to emulsify
with water, which emulsion appears as a jelly-like substance. It might
be added that high-grade oils having a high viscosity might not be the
most suitable for turbine use.

Since the consumption of oil in a turbine is so very small, being
practically due only to leakage or spilling, the price paid for it
should therefore be of secondary importance, the prime consideration
being its suitability for the purpose.

In some cases a central gravity system will be employed, instead of the
oil system furnished with the turbine, which, of course, will be a
special consideration.

For large installations a central gravity oiling system has much to
recommend it, but as it performs such an important function in the power
plant, and its failure would be the cause of so much damage, every
detail in connection with it should be most carefully thought out, and
designed with a view that under no combination of circumstances would it
be possible for the system to become inoperative. One of the great
advantages of such a system is that it can be designed to contain very
large quantities of oil in the settling tanks; thus the oil will have
quite a long rest between the times of its being used in the turbine,
which seems to be very helpful in extending the life of the oil. Where
the oil can have a long rest for settling, an inferior grade of oil may
be used, providing, however, that it is absolutely free of acid.

V. PROPER METHOD OF TESTING A STEAM TURBINE[3]

[3] Contributed to _Power_ by Thomas Franklin.

The condensing arrangements of a turbine are perhaps mainly instrumental
in determining the method of test. The condensed steam alone, issuing
from a turbine having, for example, a barometric or jet condenser,
cannot be directly measured or weighed, unless by meter, and these at
present are not sufficiently accurate to warrant their use for test
purposes, if anything more than approximate results are desired. The
steam consumed can, in such a case, only be arrived at by measuring the
amount of condensing water (which ultimately mingles with the condensed
steam), and subtracting this quantity from the condenser's total
outflow. Consequently, in the case of turbines equipped with barometric
or jet condensers, it is often thought sufficient to rely upon the
measurement taken of the boiler feed, and the boiler's initial and final
contents. Turbines equipped with surface-condensing plants offer better
fa