Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1909-11-19
WATCH MAiNsPRINGs.
Why They So Often Break Puzzlins
Conundrum.

Why They So Often Break Puzz''ns
conundrum.
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 fickle handspring concluded to
resign the task and, well-simpiy
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?"
"Who Struck Billy Patterson?'
and other unanswered questions OF
history. The best mainsprings 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 searching, Is rewarded. Sudden
electrical disturbance Of the atmos-
phere, extreme changes of tempera-
ture, or contact with a cold substance
will occasionally result in a broken
handspring. Such contingencies are
we'll 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 1t to 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
piece Of tempered steel, usually about
twenty inches long, coiled in a barrel
between the upper and lower plates
of the movement. 1t is the motive
power Of the watch. 1t Is made In
degrees of strengths, widths, and
thicknesses suitable to the watch. AS
a handspring is subjected to varying
conditions, from that Of highest ten
sion when fully wound to that or
comparative rest when the watch is
run down, and as it is constantly un-
dergoing a change in resistance as It's
coils unfold, it seems to be the only
part Of the watch, subject to casual
ties against which even careful use
cannot always provide.
1t may be we'll to state, just here,
that all watches of given make and
size do not properly take the same
strength of spring. A variation In
thickness Of only two 1000 OF an
inch may be the measure Of the diff
ference between the right and the
wrong handspring for your watch.
Here is the field Of the qualified watch
quires some deftness; but to fit the
proper one demands practical expe-
rience and Judgment If your watch
is worthy of a spring at all, pay
competent matchmaker proper
charge for good one.
But the question, why do watch
springs break?" remains unanswered,
and the puzzle is still further COM
plicated when we are informed by one
of the largest manufacturers OF
watches in the world, that sudden
spell of hot weather Is invariably sue
ceeded by a noticeable increase in the
number of complaints Of broken
watchspring. At first thought this In
formation Is puzzling. A sudden drop
rather than q sudden rise in tempera-
ture would seem to be the natural
predisposing cause. Cast metals
show greater brittleness at low tenn
peratures under all kinds of stress,
and steel and iron, though at low tenn
peratures they show but little loss of
strength under static or under grad
ually applied stresses, show 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
heated trousers or vest pocket and
laid suddenly on cold marble or iron
slab; but how shall we explain the
sudden breaking Of the spring while
the watch Is running undisturbed In
the pocket? Here is question
which we commend to consideration
and discussion by our readers.-Scien-
tiflc American.