Why Do Watches Have Jewels?

When a watch is advertised, the number of jewels it has is often mentioned as an indication of its quality. What exactly is a “jewel” in a watch, and why is it there?

A watch (or clock) is only useful to us if it is accurate, and if it doesn't constantly break down. The average watch contains about 211 different pieces, so obviously it's quite a complicated mechanism. Let's see what makes a watch go and the part that jewels play in this.

A watch gets its power from the mainspring, which is a coiled wire about two feet long when straightened out. When you wind the watch, you tighten the coil of the mainspring.

From the mainspring, the power travels through a series of four wheels, called the train, to the balance wheel. The train moves the hands on the dial. The balance wheel acts like the pendulum on a clock. It is the heart of the watch and regulates it movement.

Inside the balance wheel is the hairspring, a coiled steel wire no thicker than a hair. One pound of the right steel will produce eight miles of this wire!

Around the the edge of the balance wheel are adjusted tiny screws of steel or gold. There are various wheels that constantly move in a watch. These wheels rest on pivots, and the constant motion creates friction.

To withstand this friction, the pivots rest on tiny pieces of precious stones, such as ruby, sapphire, or garnet.

These are the jewels of a watch. The more jewles, the less likely is friction to wear out or slow up the moving parts in your watch!

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