SHEFFIELD CORPORATION has now connected up what is probably the largest individual user of electricity in Great Britain to its supply mains, in creasing the supply by more than thirty per cent. Messrs. Thomas Firth and John Brown, Ltd., of Shef field, have works covering 140 acres, and formerly had two generating stations of their own having a capacity of 20,000 kilowatts. Now they have abandoned these, and obtain energy from the public supply mains. Generally speaking, there are many reasons for taking this course. They will be able, for example, to concentrate on their own particular processes of production, leaving the generation of electricity to experts. The space formerly occupied by the boilers and turbines of the private plants can now be utilised for extensions. The basis of the manufacturing processes carried out by the firm are in the melting house, where there are installed furnaces ranging from a capacity of 2 tons to 40 tons. The largest furnace, when melting at its peak load, requires 5,000 kilo-volt amperes. The electric furnaces alone melt 1,000 tons per week. This is much greater than the output of any other electric furnace plant in Great Britain. All the supply problems are now dealt with by the Corporation engineers, who have the Grid behind them as a reserve. The bulk supply is given to the works at 33,000 volts, and the distribution is so operated that the lowest possible simultaneous demand is made. The decision reached by this firm to take the public supply will carry great weight with other companies which are considering the problem of continuing to manufacture their own electric power or not.