These Jefferson Electric Company Coils were used in the good ole days of wireless communications.

The coils are made to step up the voltage and current. They are manufactured to operate on either dry cells or a storage battery, and were guaranteed to give the operator their full rated spark length between the needle points. These coils were made to operate from either 6 or 12 volts. Jefferson Electric Company claimed that the high efficiency of these coils would insure economy in the rate of current consumption so that the life of any battery or dry cells would not be wasted.

When the Jefferson Electric Company manufactured these coils they took special care so that the windings and condenser were balanced to virtually eliminate any arcing at the contact points. This helped to stop or reduce to a minimum any freezing and/or sticking of the points which would help to prolong the life of the points.

The points in these coils were made from tungsten. The case of these coils are made from polished mahogany. Most of the metal parts in the example here are made from brass. 

The photograph on the left is a close up of the metal manufacturers label that is nailed to the top of this coil. The photograph on the right is of the left side of the coil.

The photograph on the left is of the rear of the coil. The photograph on the right is of the bottom.

As you have probably guessed, these were rather nice looking items in their day and would have looked great sitting on the desk of an amateur radio operator of the era, or even today. They also make great items to sit on the bookshelf of the shack and can be picked up in working order fairly cheaply even today. Not to mention the many fun and exciting projects that can be built from one including a vintage spark gap radio station. Sadly though, it is now illegal to put a spark gap transmitter on the air due to it's broad band capabilities.

Another manufacturer of similar coils is the K-W company.