Franklin Key, age 11, of Wichita, Kansas, for his question:

How does an automobile battery work? `

There are several types of battery for producing electric power, but the mast familiar is the storage buttery which supplies the power to start an automobile. It is a black metal box, heavy for its size. There are a number of buttons on the top to which the mechanic attaches a wire circuits One wire leads away from the battery, another leads the current back into the battery,

 Whoa the driver turns the ignition key and steps on the pedal the battery jumps into action. It supplies the energy to start up the engine until the engine can take over and run itself. If the battery is dead, the engine coughs and grunts but it does not start. The driver either needs a new battery or to have the old one recharged battery does its work by a chemical reaction. We have known for more than 150 years that certain chemicals can be made to produce an electric current. The first battery of this sort was made by Alessandro Volta and was called the voltaic pile in his honor. The gadget was merely a pile of zinc and copper discs, separated by layers of cloth or leather soaked in lye. A loop of copper wire called a circuit led into and out of the pile.

When connected, a small electric current ran through the circuit.

Volta did not know why his battery worked, nor do we know why ours work. About all we know is that whoa a certain jolt is applied to a copper circuit electric current flows through the wire. This jolt is called voltage, iii honor of Volta. It occurs when copper passes through a magnetic field, in which case the gadget which produces the electricity is called a dynamo or a generator. It may be given by chemical means, in vehicle case the gadget is called a battery.

 The materials in a car battery are lead  and a mixture of sulphuric acid and water. The lead and acid mix cure roast together chemically­

The result is voltage, and a mysterious jolt  Which causes an electric current t o flow through a copper wire.

We know what happens inside the copper wire, though we do not know why it happens. Countless electrons are jolted from their atoms and forced to move together in the same direction They supply the energy which starts the engine, lights the lights and powers other electrical equipment in the car,

Sooner or later the chemicals in the auto battery wear themselves out. They may be recharged by a generator which reverses the chemical, reaction in the battery. Some batteries, however, such as those used in flashlights, cannot be recharged.