The Bridge
The bridge supports the strings above the fingerboard from the nut, over the bridge to the tailpiece.
Usually about 75% of the wood in the bridge is their for strength.  The other 25% of the wood actually dampens the sound, but provides a portion of the tone the violin produces.
A bridge needs to be fitted to the violin by carving its feet to match the curvature of the violin belly.  It also needs to be adjusted so that it is the proper height for the violin, and it needs to be placed in the right place on the violin.
The best guideline I can give is to place a bridge even with the slash in the f-holes.  The feet of the bridge should be placed over the sound post and the bass bar.
If you look closely at a violin bridge you will see that one side is flat, the other is slightly tapered.  As you place the bridge on a violin, the tapered side will face the tailpiece.  The flat side will face the scroll.  The flat side should form a right angle with the violin's belly.
Bridges are usually made of maple.  This is a good wood in that it is strong enough to withstand the pressure tightening the strings
will bring.  It is also a good material to carry the vibrations from the strings to the belly of the violin. Some bridges have an insert of ebony where the E-string will go to prevent its digging into the bridge.
Break a String?  Bridge Fall Down?  Rosin Building Up On Your Fiddle's Belly?  Don't Know How To Care for Your Violin?  This is a Good, Inexpensive Book on Violin Care and Maintenance that no beginner should be without!!!  Click Here to Take a Look!
Violin Tipbook