3.2.3 Development Headings

From the mine shaft, horizontal drifts were opened to follow promising areas of mineralization. In the 19^th century, in the Eustis mine for example, drifts were dug by hand with a steel bar, a rock hammer and explosives, in the era of black powder.

		Digging a plug hole by hand.
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The introduction of pneumatic air drills at the turn of the 20^th century made digging holes much easier, but increased the health hazards created by silica dust until ventilation was improved.

		Pneumatic drill, 1926.
	Source

		Jackhammer and its drillrod, 1950.
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Holes were drilled and then packed with explosives to break up the wall rock and extend the drift. In the 1890s, black powder was replaced with dynamite, which was much safer and more effective, as were the improved storage conditions for this explosive. In addition, the adoption of electricity to ignite charges instead of hand-lit wicks in the late 1910s significantly reduced the hazards associated with this essential activity.

		Igniting dynamite cartridges.
	Source

Blasting kit (cord, fuse and cartridge). Source

Detonator wire, 20th century. Source

Blasting machine, 1950. Source

If a charge failed to explode, the men had to check whether there was any current left in the wires connected to the detonator before approaching the explosives.

		Blasting galvanometer for dynamiting operations, circa 1950.
	Source

Explosion by explosion, the miners penetrated further into the orebody and removed waste rock and ore for processing.