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Foui-party-line selective ringing : A 100-line unit capable of accommodating 400 subscribers was installed at the Central Exchange. This system is giving a service much superior to that of the former manually-operated four-party lines, with which the rings were heard by all parties on the line. Equipment is installed at the Central Exchange for dehumidifying and removing dust from the air before delivering it to the rooms in which, the switching-apparatus is used. The plant is functioning successfully, and its use is reflected in reduced maintenance charges and more satisfactory operation of the equipment. An extension of 500 individual lines to provide for growth at the South Dunedin Exchange will be installed during the year 1928-29. Oamaru. —At the Oamaru Exchange equipment for an extension of 100 individual lines is now being proceeded with. When this work is completed the capacity of the exchange will be 800 individual lines and 100 four-party lines. Provision is being made for the installation during the year 1928-29 of a further extension of 200 individual lines. Wellington Metropolitan Area and District Automatic Telephone Exchanges. Wellington. —To cope with the growing demand for telephone service in the western suburbs the capacity of the Kelburn Exchange is being increased by 400 individual lines. Temporary equipment to provide for 200 individual lines [at thejMiramar Exchange was brought into service on the 13th January, 1928. Equipment for a further 200 lines is now being installed ; and this will meet requirements until the arrival of the permanent equipment under order. A number of long-distance telephone-exchange subscribers' lines connected to the Wellington Exchange and situated outside the normal dialling-range were, by the adoption of a special circuit, converted from manual to automatic working, thus enabling the subscribers to intercommunicate with subscribers in the Wellington Exchange area without the intervention of an operator at the central exchange. Napier. —The Napier Telephone Exchange was converted from manual to automatic working on the 28th August, 1927. The equipment installed at this exchange was previously in use at Auckland, and before installation at Napier, it was thoroughly reconditioned and brought up to date. The present capacity of the exchange is 2,200 individual lines, 100 two-party lines, and 100 rural lines. Dannevirlce. —The installation of the Dannevirke Automatic Exchange was completed on the 15th May, 1927, and the exchange was converted on that date from manual to automatic working. The present capacity of the exchange is 700 individual lines and 50 rural lines. Stratford. —The installation of the automatic exchange at Stratford was completed on the 2nd April, 1927, and on that date the exchange was converted from manual to automatic working. The equipment at present installed provides for 500 individual lines, 100 four-party lines, and 50 rural lines. Palmerston North. —At the Palmerston North Exchange additional equipment to provide for 400 individual lines is being installed, and the work is expected, to be completed shortly. An electric motor was installed to replace the petrol-engines previously in use for charging the storage batteries at the exchange. One of the petrol-engines, however, is being retained as a stand-by for emergency purposes, so that the continuity of the telephone service will be assured in the event of a temporary derangement of the borough electrical-supply system. Masterton. --During the year the installation of additional equipment to provide for 100 two-party lines at the Masterton Exchange was completed. An extension of 200 individual lines is now in course of installation, and will be cut into service at an early date. Wanganui. —Provision is being made at the Wanganui Exchange for an extension of 200 individual lines to provide for normal growth in this area. Blenheim,. —The switching accommodation for exclusive lines at the Blenheim Exchange has been fully absorbed, and equipment for an extension of 100 individual lines is now being installed. " Interphone " Installations. There has been a substantial increase in the number of " Interphone " installations throughout the Dominion. This system which provides for inter-departmental communication and for outgoing calls to the central, exchange to be made without the aid of a local switching attendant, is proving very popular. In Wellington City alone 45 additional installations (240 key-boxes) have been completed, making a total of 242 installations (1,612 key-boxes) in use at that centre. Automatic Private Branch Exchanges. There is a steady demand for the installation in business houses of automatic private branch exchanges where the " Interphone " key-box system does not fully meet requirements in regard to capacity, secrecy, or variety of services rendered. So far six private branch exchanges have been installed in Wellington and three in Auckland. Thirty-five more automatic private branch exchanges are under order for installation in different auto-matic-exchange areas.