The arcing horns on a typical
vertical Switch - Air Break are circled in the figure at the right. Any Time an Air break Switch is opened - even a Light switch in your home - there is an arc present. On a switch with arcing horns
they carry the arc rather than the switch blade tip and the contacts. As the
switch opens, the horns are spread farther and farther apart, lengthening the
arc until it breaks. Since the horns are specially made to withstand the rigors
of a high-voltage arc, the switch life is greatly lengthened. Also, the horns
keep the arc on a specific path, reducing the chances of a fire breaking out.