In a generating station, cooling-tower performance must be considered not only in terms of heat dissipation but also in relation to the over-all results obtainable with a particular combination of tower, condenser, and turbine. There is an important relationship between turbine leaving losses and the optimum tower size. This approach to the subject involves not only the economic size of the tower but also certain operating problems which vitally affect the station heat rate. The problem of condenser-tube scale deposits is more likely to become critical where cooling towers are used, because of higher cooling-water temperatures. Successful results are described in the use of threshold treatment of cooling-tower water with stabilized phosphate in combination with sulphur burning for keeping condensers free of scale deposits. The problems of recirculation, fan-blade failures, and noise nuisance are also discussed.