The Miller press. [volume] (Miller, S.D.) 190?-current, 1909-12-02
WATCH SPRINGS.
They Break, but No One Seems 20
Know Why They Snap.

Your watch has stopped without
apparent cause, and you at once at.
tempt to wind it. The crown turns
with a new sense of ease, but the
operation is endless. Then you
learn that a tickle handspring con
Guided to resign its task-well, SIM
ply broke. Why? Here is a query
that may stand in the company of
"Who wrote the letters of Junius ?"
"Who was the Man with the Iron
Mask?" and other unanswered ques-
tions of history. The best main
springs have maintained their right
to break ever since modern watches
were invented, and they will do so
until some secret of nature, for
which watchmakers are still search
ing, is revealed. Sudden electrical
disturbance of the atmosphere, e1-
IRENE changes of temperature or
contact with a cold substance will
occasionally result in a broken
handspring. Such contingencies are
well understood by watchmakers.
What is not so we'll understood is
why a spring will sometimes snap in
twain or in twenty pieces despite
the best of care. You may ascribe
it to a fit of temper or to the dog
days or give any other reason that
is neither logical nor theological.
The fact and the mystery remain.
This spring is a piece of tempered
steel, usually about twenty inches
long, coiled in IA barrel between the
upper and lower plates of the move
ment. 1t is the motive power of
the watch. 1t is made in degrees
of strength, width and thickness
suitable to the watch. AS a main
spring is subjected to varying con
ditions, from that of highest ten
sion when fully wound to that of
comparative rest when the watch is
run down, and as it is constantly
undergoing a change in resistance
as its coils unfold, it seems to be
the only part of the watch subject
to casualties against which even
careful use cannot always provide.
1t may be we'll to state just here
that all watches of a given make
and size do not properly take the
same strength of spring. A varia-
ton in thickness of only two one
thousandths of an inch may be the
measure of the difference between
the right and the wrong handspring
for your watch. Here is the field
of the qualified watch repairer. To
fit a handspring requires some deft-
ness, but to fit the proper n de-
mands practical experience and
judgment. If your watch is worthy
of a spring at all, pay a competent
matchmaker a proper charge for a
good one.
But the question, "Why do watch
springs break" remains unanswer-
ed, and the puzzle is still further
complicated when we are Informed
by one of the largest manufacturers
of watches in the world that a sud-
den spell Of hot weather is invari-
ably succeeded by a noticeable in
crease in the number of complaints
of broken watch springs. At first
thought this information is puz-
zling. A sudden drop rather than a
sudden rise in temperature would
seem to be the natural predisposing
cause. Cast metals show greater
brittleness at low temperatures I'M
der all kinds Of stress, and steel and
iron, though at low temperatures
they show but little loss of strength
under static or under gradually ap-
piled stresses, show a marked loss
under impact or sudden stress.
We can understand the breakage
of a handspring when in very hot
weather the watch is taken from a
heated trousers or vest pocket and
laid suddenly on a cold marble or
iron slab, but how shall we explain
the sudden breaking of the spring
while the watch is running undis-
turbed in the pocket? Here is a
question which we commend to con-
sideration and discussion by Jul
roadarc Scientific American