This is obtained by causing one of them to send a series of signals from one particular key, while the operator at the other station adjusts his speed until he receives the same signal after shortcircuiting his electromagnet for ten revolutions.
The quadrate muscle adjusts the motion, and prevents pressure upon the optic nerve; during the state of relaxation of both muscles the nictitans withdraws through its own elasticity.
The stationary wave system adjusts itself so that its motion agrees with that of the sounder, which is therefore not exactly at a node.
Thompson and others have shown however that they contain both neutral and charged molecules in a relative proportion which adjusts itself continuously, so that even neutral molecules may partake of the translatory motion which they gained while carrying a charge.
In reality, the tension adjusts itself automatically to the weight to be supported at the various levels.