What Is A Watch?
In the 1950's, Elgin wrote this short little booklet entitled "what is a
watch?" to help customers understand what they were buying. This
booklet still makes a great introduction to mechanical watches. While
it was made by Elgin and is geared toward wrist watches, it is general
enough to apply to pocket watches and watches from most companies.
Table of Contents
case materials
karat gold
thickness of case
dust and moisture
water-resistant watches
dials and numerals
how a watch runs
the mainspring
the DuraPower mainspring
when your watch ticks . . . .
the hairspring and balance wheel
Jewels
where they are
adjustments
shock-resistant watches
automatic watches
a quality watch . . . . .
Karat gold is an alloy of pure gold and other metals. A layer of
karat gold over another metal is called gold filled or rolled gold
plate depending on thickness. Stainless steel may be used in the
whole case or for the back only.
|
Karat is the measure of gold content. Pure gold is 24K. 14K means 14
parts of gold and 10 parts of other metals by weight.
|
 |
The proportion of gold (karat) does not give an indication of the
total amount of gold in the case. Usually, the thicker a gold case,
the stronger it is.
| 14k gold cases |
| Thin and flimsy |
Thick and sturdy |
 |
 |
|
Dust and moisture may enter a watch in three places -- around the
crystal, at the joint between parts of the case, and at the winding
stem. The closer the fit of these parts, the better the quality of
the watch case. No matter how fine the watch movement, if it is not
protected by a good case the watch will not function properly.
|
 |
|
Water resistant watches have gaskets in the case back and around the
crown to keep water from getting into the watch. If removed, the back
must be put on by a jeweler to assure water resistance. Plastic
crystals seal themselves. Gaskets are used to seal glass crystals.
|
 |
|
The dials of most dress watches are sterling silver or silver coated.
Numerals may be printed, embossed or applied. Embossed numerals are
raised on the dial. Applied numerals and markers, used in highest
quality watches, are 18 karat gold and are mounted separately.
|
 |
Power in a coiled spring (1), released in small quantities at exact
intervals (2), turns gears on which are the hands that register the
time on a dial (3).
- The power that runs the watch comes from the mainspring.
- The escape mechanism releases the power in small quantities at
exact intervals.
- The train is the set of gears that turns the hands and drives the
escape mechanism
 |
The mainspring is the power plant of a watch. When you wind your
watch, you put power into the mainspring by coiling it up. Most
mainsprings are made of carbon steel. The most common cause of
mainspring breakage is rust.
|
 |
|
The Elgin DuraPower mainspring is made from "Elgiloy." It is
unaffected by moisture. It will not rust. The DuraPower mainspring
is guaranteed to never break in service.
 |
| Magnified rust pit in a steel
mainspring |
|
After 18 days of exposure to extremely moist conditions the DuraPower
mainspring (right) is free of rust. The steel spring (left) has
disintegrated.
|
|
Power from the mainspring must be controlled so the watch will keep
time. The escape mechanism lets this power escape in equal amounts at
short intervals. This is what causes the ticking of your watch.
Elgin has created a rust-proof alloy escape wheel that is so durable
as to be unaffected by the continuous pounding the wheel must take.
|
 |
|
The steady rate at which your watch ticks is controlled by the
hairspring and balance wheel. At each tick the hairspring expands or
contracts, the balance wheel swings one way or the other, and the
hands move. Because of their importance to the life and accuracy of a
watch, Elgin balance wheels are made of Beryl-X, a special alloy
developed by Elgin. The hairsprings are made of a special alloy
called Elginite.
|
 |
Excessive friction causes wear which destroys the accuracy and
precision of a watch. In higher quality watches, certain parts move
on bearings made of tiny jewels, usually sapphires or rubies.
Hole Jewel
|
Hole and Cap Jewel
|
| |
Pallet Stone Jewels
|
Roller Jewel
|
- The basic 7 jewels are part of the escapement and balance and are
found on all Elgin watches. They include cap and hole jewels for both
the top and the bottom of the balance wheel (total of 4), the two
pallet jewels and the roller jewel.
- The next 8, making 15 jewels, are hole jewels for the fast moving
part of the gear train.
- The next 2, making 17 jewels, are hole jewels on the center wheel.
- The next 2-4, making 19-21 jewels, are cap jewels on the escape
wheel and the pallet fork.
|
Quality watches are adjusted at the factory to make sure they will not
gain or lose time under varying conditions. An adjusted watch is
marked "adjusted" on the mechanism.
|
To position
|
| |
|
|
| For Temperature |
For constant time (which compensates for how tightly the
mainspring is wound.) |
|
In a shock resistant watch the jewels that carry the balance staff are
mounted in springs. The springs take up shock and help prevent
breakage of the jewels or staff.
|
Jewel mounted on spring
|
 |
 |
 |
| Normal position of balance staff |
Shock, down and sideways taken up by
spring |
Jewel on Balance |
|
The slightest movement of your wrist winds an automatic watch. A
pendulum, mounted in jewels, winds the mainspring a small amount each
time it swings.
|
 |
is one of the finest, most precise, most carefully made mechanisms in
the world.
To be sure of quality, put your trust in a known watch.
Be sure it will give complete satisfactory operation.
Be sure your jeweler can service it quickly--economically.
Scans of this brochure are complements of
Tom McIntyre.
It should be noted that many of the hyped materials mentioned in this
brochure such as Beryl-X balances, Elginite hairsprings and Elgiloy
mainsprings were not really unique to Elgin. Most other watch
companies had similar materials, although Elgiloy is special enough
that 50 years later, it is
still being sold.
|
![[Elgin home]](../images/elgin_logo.png){kind=logo}
