The San Juan islander. [volume] (Friday Harbor, Wash.) 1898-1914, 1905-12-02
CAR WHEELS AND CURVES.
Scientific American Answers Questions
Regarding Them.

Regarding Them.
One of the questions from CORE
spondents that comes to this office
with persistent reiteration is that Of
the possibility Of one or the other Of
the pair of wheels on a railroad axle,
in passing around the curve, slipping
on the rail over which it is rolling,
while the other wheel does not slip
on its rail, says the Scientific Ameri-
can. Although we have frequently ex-
planned how this condition is possible,
the question is one that evidently
continues to puzzle great many
peOple-in which respect it is first
cousin to that other much-de-
bated fact, that the portion Of
the periphery of rolling cart
wheel that is near the ground is NOV
ing more slowly with relation to the
earth than is the rest of the periphery
In the case of the two wheels on any
axle Of railroad or trolley car that
is passing around a curve'it is evident
that in given length, say 100 feet of
the curve, measured on a line lying
centrally between the two rails, the
inner rail will be shorter than the
outer rail, and this for the reason that
it Is struck to a radius that is about
four and three-quarters feet shorter
Now, when a pair Of wheels passes
around the curve it follows that, be-
cause of the difference in length of
the two rails, either the inner wheel
must slip backward on the inner rail
or the outer wheel slip forward on the
outer rail, for the two wheels, being
fixed on the same axle, move at the
same peripheral speed over different
lengths Of rail in the same time
It is probable that the excessive
wear Of the rails on curves is due
chiefly to the slipping of the wheels.
Not long ago some remarkable facts
on rail wear on curves were brought
out in the course of paper read be-
fore the New England Street Railway
Club by the roadmaster of the Boston
elevated road. The road is exceeding
ly crooked, over 40 per cent of the line
consisting Of curves. many Of which
are very sharp. There are eighteen Of
less than 1OO-foot radius and sixteen
others with radius of less than $50
feet. On the sharpest curve, which is
of only 82-foo+ radius and where it is
claimed that re traffic is heavier than
that on any @ her steam or heavy cleo
| trio railroad the life of ordinary steel
rails averages only forty -four days, the
head of the rail wearing down from
O.6O to OFT Of an inch in that time.
The great inconvenience caused by the
constantly recurring repairs led >the
company to experiment with hardened
steel rails and when some nickel steel
rails were put in on the curves the
wear was reduced to O.53 of an inch
] in 2O4 days. A manganese steel rail
| is now being used with good results
and the wear of these is only about 80
per cent as rapid as that OF the nickel
steel rail and about 6 per cent as rapid
as that of the carbon steel rails.
ARue.
"Rut thought you told me this was
such congenial country said the
man who had just moved out in the
| suburbs.
And 1t Is" replied the suave agent
| why, it is full of malariar'
And that is why / think it is SO
congenial. You see everybody Is al
ways shaking"
Natural Deduction.
Grun PatientAre you quite sure
you understand your business, sir?
Physician-Well, I've been practic-
ing medicine for fifteen years and not
one of nv nafienfa has avor rovy,