Abstract: A method of breaking rock, concrete or other hard compact material adjacent to a hole drilled thereinto and an apparatus for performing the method wherein the apparatus contains a notch-forming means to form a circumferential notch in the drillhole wall, a hydraulic jack means which is located inside the drillhole to exert a force to actuate the notch-forming means and to react against the bottom of the drillhole and develop an outwardly directly axial force on the notcher to break one or more pieces of material from the face and a hydraulic supply means to supply hydraulic fluid to actuate the hydraulic jack. The hydraulic supply means is located outside the drillhole.