The frequency that wouldn´t die hydroelectric generators

North America´s Niagara River is the site of operating 25 hertz hydroelectric generators that date to the dawn of the electrical age. The reasons why 25 Hz was chosen for such a large block of power and why that obsolete frequency has lived on for the better part of a century are examined. The reasons for its choice lie in the conditions and attitudes of the period, and it has remained because changing frequencies is very expensive for the customer.<>