Abstract: A device for and a method of automatically drilling a selected number of longitudinally spaced holes to a depth of up to twelve feet during an uninterrupted operation in a mineral surface usually granite. The device includes a support frame carrying a drill assembly for vertical and longitudinal movement. The drill assembly comprises a carriage, a mast and a housing which mounts at least one drill carrying a drill steel or rod. A programmable computer controls a plurality of drives to move the drill assembly from a raised position into a drilling position adjacent a desired surface. The programmable computer then activates the drill to drill a hole of a prescribed depth after which it deactivates the drill. The drives are now activated to retract the drill assembly and to return it to it's raised position. The programmable computer then controls the drive to index the drill assembly along the support frame into a successive drilling position.