Various types of vibration are discussed with special emphasis on the large and uncommon type of vibration known as "galloping". The effect of an ice coating on the line was investigated and could not be proved to enhance vibrations artificially introduced into the line. A mathematical expression for the period when the cable sways in the wind was developed. This period was found to be approximately equal to the period of the "fundamental" of the span. After various experiments had been carried out, the conclusion was reached which attributed the cause of galloping to pulsating winds.