Small vessels like these were turned on a simple bow lathe (drawing below). The open cylindrical shape and smooth surface of these bowls are typical of vessels turned on a lathe. (Chisel marks were generally left on handmade vessels, such as the “measuring cups,” opposite.)

Still used in some traditional societies today, bow lathes have a sturdy, adjustable wooden frame with two spindles—one fixed and one rotating—that hold the stone in place from either side. After the block is roughly cut down by hand, it is soaked in water to soften the stone and keep it from cracking. Then the outer and inner faces are worked with a chisel to a rough approximation of the desired shape. Next, a wooden spool is firmly affixed (usually with hot tar) to what will become the bottom of the vessel, and the stone is mounted sideways in the lathe. The fixed spindle (at left in the drawing) is set in an adjustable headstock and is pressed firmly against the top of the vessel to support and align the stone but not so tight as to keep it from moving. The other spindle (at right) remains unfixed and thus is free to rotate. The string of the bow is looped around the spool. With one hand, the artisan moves the bow back and forth, thereby rotating the spool and the vessel. With his other hand he shapes the vessel with iron knives. After the outer face of the vessel is roughly turned, what remains inside is removed by deep cutting and the core is detached. Finally, the outside of the vessel is smoothed with a sharp knife to obtain extremely thin walls.