At the request of the Defence Supply Planning Branch of the Department of Supply an investigation of the Australian graphite industry was undertaken early in 1950. The particular aspects to be considered in this investigation were listed by the Planning Branch as follows: the specific defence significance of graphite and an estimate of peace and probable wartime demands, the experiences during World War II where applicable, the present and future supple position, alternative methods of ensuring that demands are met in an emergency, and the method recommended to meet demands in an emergency. This report should be considered an interim report containing recommendations for early consideration by the Planning Branch.

The Great Cobar ore deposit was discovered in 1870. Production commenced in 1871 and since that date mining at Cobar has been more or less continuous. The field has produced copper, gold, and silver to the value of approximately £A27,000,000. Cobar has been the most important producer of copper in New South Wales, and in recent years, has also been the most important gold-mining centre. The Zinc Corporation Limited is carrying out, with the aid of the Bureau, an extensive geological and geophysical examination of the area, with the hope of finding other orebodies. The Bureau itself has extended geological mapping over an area of approximately 2,000 square miles in the Cobar-Nymagee-Canbelego district with the ultimate aim of discovering other ore deposits, or even fields of the Cobar type. In the Nymagee district, North Broken Hill Limited is also carrying out, in co-operation with the Bureau, an extensive exploration programme. The history, production, reserves and prospects of the New Occidental, Chesney, and New Cobar mines are discussed in this report.

The mica used in modern aircraft sparking plugs, of which the attached section is representative, serves a triple purpose, viz: (a) Insulation of the electric current; (b) Protection of the insulating layers from heat; (c) As an effective seal against gas leakage. The use of mica in the construction and manufacture of aero engine sparking plugs is decribed herein.

These notes are supplementary to an earlier report (1948/016), and are designed to elucidate certain points brought up in that report. The issues of grade, workings, development, expenditure, production, and future prospects are generally discussed.

Report on mine maintenance, costs, equipment, employment, reserves, and workings.

Report on mine maintenance, costs, equipment, employment, reserves, and workings.

Report on mine maintenance, costs, equipment, employment, reserves, and workings.

Report on mine maintenance, costs, equipment, employment, reserves, and workings.

Report on mine maintenance, costs, equipment, employment, reserves, and workings.

Report on mine maintenance, costs, equipment, employment, reserves, and workings.