another. One method is to insert a hot-wire current meter between the antenna and the inductance, which will indicate the strength of the oscillatory current set up in the same. By manipulating the flexible connections, a maximum reading will be obtained, which will indicate that the two circuits are in synchronism.
In the other method a device is used which accurately indicates the wave length. With this instrument the frequency of one circuit can be measured, and then the other circuit adjusted to give a corresponding wave length.
Since the wave length is dependent on the frequency of oscillations, which in turn is dependent upon the capacity and inductance of the oscillatory circuits, it should be clear that the larger the antenna, the longer will be the wave length, and, necessarily, the greater the capacity of the Leyden jars. The power required is always in proportion to the wave length; that is, for the most efficient results.
In practice it is customary to use a short wave length for low-power short-distance equipments, and a long wave length for high-power long-distance systems. This may be readily understood when we consider that more energy is required to make long, deep waves in water, than is required for the short and shallow waves.
