Focus on this artwork and explain the Fabrication technique.
Powers conceived of the Greek Slave as an artwork that would be produced in one or more finished marble statues, a common practice in nineteenth-century sculpture studios. He and his contemporaries rarely carved the final marble products themselves, relying instead on  teams of skilled artisans to produce the finished works on their behalf.  After he completed a full-scale clay model of the sculpture in his studio in Florence, Powers gave the model over to professional plaster casters. The casters created a multi-part plaster mold, which was used in turn to cast a durable plaster version of the sculpture.  Metal armatures inside the form provided support; these can now be seen in modern x-ray images.
Master carvers then used the durable plaster cast as a measuring tool, covering the surface of the plaster cast with hundreds of pencil marks and metal pins, or points, which served as registration marks for a pointing machine. The pointing machine was moved repeatedly from the points on the plaster cast to corresponding areas on a block of marble to guide the carver's tools as he translated the composition into marble. The tool would then be moved, over and over again, hundreds of times, from the points on the plaster to the corresponding locations on the block of marble. Each time, the tool would measure the depth and location on the marble block, creating a three-dimensional guide that helped the marble carver replicate the artist's original form more quickly and with greater ease. When creating the finished marble versions, fine details such as the cross, locket, and chains were finalised, and differ slightly among the marble versions. The Smithsonian American Art Museum holds the original 1843 pointed-plaster mold, along with numerous smaller casts from Powers' studio.
Florence Smithsonian American Art Museum pointing machine Greek