Until about 1900 all ivory carvers used much the same tools: an ax, adz, or chisel for removing the outer bark, or rind, from the tusk; a bucksaw or bow saw for cutting the trunk of the tusk into sections; a special tool called a float for paring the surface; and hand chisels, fretsaws, and gauges for actually carving the piece. The great change came with power-driven rotary saws for cutting and peeling the ivory and with dental drills for carving it easily and quickly. These machine tools spread from Europe to Asia in the mid-20th century and are now in universal use for carving ivory.