in the air. To work a 20-mile distance the line should be
100 or 150 ft. above the ground. A good way is to erect a wooden
pole on a house or barn and carry the aerial wire to the top and
out to the end of a gaff or arm.
To the end of the aerial wire fasten a bunch of endless loops made
of about No. 14 magnet wire (bare or insulated), attaching both
ends to the leading or aerial wire. The aerial wire should not
come nearer than 1 ft. at any point to any metal which is
grounded.
Run a wire from the other binding post, A, to the ground and be
sure to make a good ground connection.
For simple experimental work on distances of 100 ft. only, an
ordinary automobile spark coil can be used in place of the more
elaborate coil, Figs. 1 to 4.
The above-mentioned instruments have no patents on them, and
anyone is at liberty to build and use them. The writer does not
claim to be the originator, but simply illustrates the above to
show that, after all, wireless is very simple when it is once
understood. The fundamental principles are that induction travels
at right angles, 90 degrees, to the direction of the current.
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