At the end of the 1890s, the important minerals around the Mareeba area were wolfram and molybdenite, used for hardening and strengthening steel. These were mined mainly at Wolfram Camp, Mount Carbine, Mount Perseverance and Bamford. In May 1915 Queensland's first secure Labor government was elected into power. Under the leadership of T J Ryan, and with many members drawn from Queensland's northern mining fields and a policy of State capitalism, the Queensland Government set about implementing a policy of acquiring State enterprises to compete on the free market. There was a pre-World War I boom in wolfram in both Australia and Europe, to supply armament industries. However, a wartime ruling banning the sale of ore to foreign buyers prompted the Queensland Government to assist the local mines by building a State Battery at Bamford and an Assay Office in Mareeba.