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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 . . . . .

case materials

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 gold

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.

thickness of case

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

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

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.

dials and numerals

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.

Printed

Embossed

Applied

how a watch runs

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).

  1. The power that runs the watch comes from the mainspring.

  2. The escape mechanism releases the power in small quantities at exact intervals.

  3. The train is the set of gears that turns the hands and drives the escape mechanism

the mainspring

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 DuraPower mainspring

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.

when your watch ticks . . . .

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 hairspring and balance wheel

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.

Jewels

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

where they are

  1. 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.

  2. The next 8, making 15 jewels, are hole jewels for the fast moving part of the gear train.

  3. The next 2, making 17 jewels, are hole jewels on the center wheel.

  4. The next 2-4, making 19-21 jewels, are cap jewels on the escape wheel and the pallet fork.

adjustments

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.)

shock-resistant watches

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

automatic watches

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.

a quality watch . . . . .

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.

While I'm not an expert, I believe the information on this page is correct. Please send suggestions and corrections to the webmaster.
This web site runs on 100% Open Source Software. This web page was last changed on 10/04/2002 at 00:41:30.