A power drill at the Echo Mining Company mine, Mojave Mining District, ca.1900

Photograph of a power drill in operation at the Echo Mining Company mine, Mojave Mining District. Dust is generated at right. The drill is anchored in spot with a jack expanded into a crack. The drill's power line leads to the left. Several metal rods (drill bits?) and shoring are visible at left.

莫哈韦采矿区（Mojave Mining District）回声矿业公司（Echo Mining Company）矿井内正在作业的电动电钻（power drill）实拍照片。画面右侧产生作业粉尘。该电钻通过将千斤顶（jack）撑开卡入矿井裂隙的方式完成锚定固定。电钻的电源线向左延伸。画面左侧可见数根金属杆（疑似钻头（drill bits））与采矿支护构件（shoring）。