The sun., 1918-10-27
Only Perfect Lubri-
cant in All Attitudes
and Temperatures
Farme rs Asked tc
Plant Extensively


scouting and bombing flying machines
might fail at critical moments Castor oil
is the one lubricant capable of meeting in
every particular the demands of aeronau-
teal engines.
The prOpellcrs of the aircraft are turned
at far greater number of revolutions q
minute than the engine Of an automobile.
At every impulse stroke there is devel-
oped within the cylinder of the airplane
engine iniiamed gas of very high temper
allure, and this intense heat will attack and
consume most mineral oil lubricants, i'm
pairing the proper functioning of the
motors power transmitting parts.
II the high temperature of combustion
burns up the lubricating oil or thins it out
so that it no longer furnishes the required
anti-frictional film between contiguous
metal surfaces, then the pistons. &C., be-
come overhot, expand, jam, and the ma
chine is brought to standstill. The pilot
may be too far back of the encmy's lines
10 volpiane earthward and behind his own
lines; he may be in life and death
struggle with rival airmen; he may. be
maneuvring too close to the earth to make
1t possible for him to glide harmlessly TO
the ground; or he may be engaged under
other conditions that invite grave injuries,
il not certain destruction, should the en-
CINE stall.
1t is not merely question Of supplying
a lubricant that will stand up under the
internal stresses imposed by the explosive
mixtures within the motive cylinder, but it
is equally essential that the oil maintain
its body at all times and flow freely
through the distributing system, whatever
be the temperature OF the enveloping at
mospkere. The thermometer may give
reading at the ground that marks the heat
of summer day, and yet aloft the air
man may be working in rarefed strata
considerably below the freezing point The
lubricant must not CONCEAL, it must cir
eulate freely from the reserve tank ard
feed steadily into the pistons and valves
and do its work without hitch.
Indifferent to Heat and Cold
Castor oil fulfils every requirement at
the points OF application and, further, it
is singularIy Indifferent to heat and TO
cold, preserving pcrsistently under ex-
tremely wide Ianges Of temperature both
its bady and its fuidity. Months ago,
when It was realized that cur suplane
production would probably call for an i'm
mense quantity Of lubricating oil, the
authorities in Washington promptly
secured the country to take stock Of the
existing supplies OF castor oil. Their in
quiries developed the fact that we were a
long way short of being able to meet the
prospective demands.
= According to the estimates of the equip
ment division Of the Signal Corps We were
likely to need 5,000,0 900 gallons Of castor
oil, and the question was where We were
10 get anything like that quantity. For
weeks the specialists of the division worked
upon this problem, and none more zeal
ously than the late Capt. o. J. May. His
particular duty was that of testing out
the various proposed substitutes or hleHds,
it.h Ih ~ ilc cNScilidi SiHll
lation OF actual service aloft the testing
engine was installed in q special c0Inpart-
nent or chamber, where the atmospheric
pressure, &C., could be altered to approx
innate the circumstances of high attitudes
II was not merely question of lubri-
eating the motor efficiently for short
period of time. Knowing that our bat
ling airmen might be called upon to make
continuous flight of many hours, during
winch t;,eir engines would have to work
unin;aruptedly far aloft or again close
10 earth. no trial would answer that did
not provide a thoroughly demonstrated
margin of safety, so far as fabrication
was concerned. To this end endurance
tests covering unbroken intervals of one
or two days were made. The net result
II e l.. IL I