A. A metal rod fixed in the earth, running up the whole height of a building, and rising in a point above it.

Q. What metal is the best for this purpose?

A. Stout copper wire.

Q. Why is copper wire better than iron?

A. 1st—Because copper is a better conductor than iron:

2ndly—It is not so easily fused or melted: and

3rdly—It is not so much injured by weather.

Q. What is the good of a lightning-conductor?

A. Metal wire is a most excellent conductor; and as the lightning makes choice of the best conductors, it would run down the metal wire, rather than the bricks of the building.