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Dunedin Metropolitan Area and District Automatic Telephone "Exchanges. Dunedin. —During the year the installation at the Dunedin Central Automatic Exchange of 4,000 exclusive lines, 100 two-party lines, 100 four-party lines, and the toll-board has progressed steadily. It is now within measurable distance of completion, and it is expected that the conversion of the present manual system to full automatic operation will be effected about the end of May, 1927. The Dunedin Central Automatic Exchange has an ultimate capacity of 10,000 lines, while South Dunedin and Roslyn have each an ultimate capacity of 2,000 lines. At the Roslyn Automatic Exchange the present installation will provide for 1,000 exclusive lines and 100 two-party lines, and at South Dunedin, for 1,300 exclusive lines and 100 two-party lines. The installation of an air-conditioning plant at the Dunedin Central Automatic Exchange is complete except for final testing, which is uow being proceeded with. Oamaru. —The Oamaru Automatic Telephone Exchange continues to provide an efficient and smooth-running service which is equal to all demands made upon it. An extension of 100 individual lines and 10 rural lines will be installed during the year 1927-28. Wellington Metropolitan Area and District Automatic Telephone Exchanges. Wellington. —The capacity of the Khandallah Automatic Exchange was increased by 200 individual lines, and that of Wellington South Exchange by 400 individual lines. The switch-room accommodation at the Courtenay Place Automatic Exchange is being doubled to provide for an additional 1,000 individual lines, 100 two-party lines, and 200 private automaticexchange lines. Extensions of 400 individual lines at the Kelburn and Wellington South Automatic Exchanges respectively will be commenced during the year 1927-28. The question of linking up with the Wellington Automatic Exchange system the telephone subscribers in the Lower Hutt and Petone areas has been receiving close attention. The work, which will be of some magnitude, involves additional building-accommodation and the installation of expensive automatic switching-equipment, telephones, &c. The erection of an automatic-exchange building at Miramar, to serve the Seatoun-Lyall BayMiramar area, is nearing completion. Automatic equipment to provide for 1,000 individual lines and 100 four-party lines will be installed in the new building, and when cut into service the congestion at the Wellington South Automatic Exchange will be relieved. Masterton. —At the Masterton Automatic Exchange additional switching-apparatus to provide for 200 exclusive lines and 100 two-party lines is in course of installation, and will be completed during the year 1927-28. Napier.—Steady progress was maintained with the installation of the automatic-exchange equipment at Napier. The wiring is now nearing completion and is being tested, and it is expected that everything will be in readiness for converting this exchange to the automatic system of operation before the end of July, 1927. Palmerston North. —Owing to the delay in the receipt of material from overseas for the completion of extension equipment, the connection of a number of waiting subscribers at the Palmerston North Automatic Exchange has been temporarily held up. To relieve the position, arrangements have been made to transfer sufficient equipment from elsewhere to provide service meantime. The installation of an additional 400 individual lines will be commenced during the year 1927-28. Blenheim. —Additional equipment to provide for 100 individual lines and 10 toll lines is under order and will be installed during the year 1927-28. " Interphone " Installations. The " Interphone " intercommunicating telephone system used in conjunction with trunk lines to departmental automatic exchanges has proved a popular adjunct to business houses, and its use is being extended throughout the Dominion. Automatic Private Branch Exchanges. A number of private branch exchanges of the automatic type have recently been installed in large business establishments at Wellington, and a commencement is now being made with installations at Auckland. Users of this system have expressed entire satisfaction with the service given, and orders have been placed for the supply of thirty exchanges of this type. Automatic private-branch-exchange apparatus is not stocked by the Department, but is specially assembled at the factory to meet the varying requirements of subscribers. A recent development of the automatic branch-exchange equipment provides for the use, at selected extension stations, of a special type of " call-back " telephone which enables an outside caller on a trunk line to be held while information is obtained from a local extension telephone, and the conversation resumed on the trunk line when desired. This special " call-back " feature involves the use of two pairs of wires, instead of the usual one pair, between the private branch exchange and each extension station where a " call-back " instrument is installed. In addition, the cost of the " call-back " telephone is double that of the ordinary automatic telephone, while the maintenance costs are proportionately higher. The rate for automatic " call-back" private-branch exchange stations has been fixed at £6 10s. per annum.