drill, and can now obtain almost any metal we wish.

"'Magnetic eyes' are of great use to miners and Civil engineers.

These instruments are something like the mariner's compass, with

the sensitiveness enormously increased by galvanic currents. The

'eye,' as it were, sees what substances are underground, and at

what distances. It also shows how many people are in an

adjoining room--through the magnetic properties of the iron in

their blood--whether they are moving, and in what directions and