A black-and-white stereographic photograph shows the interior of the Pacific Rolling Mills, featuring two nearly identical side-by-side images mounted on a yellow card. In the center of each image, five men wearing hats and dark work clothes stand on a dirt or metal floor among heavy industrial machinery and vertical support beams. Several of the men hold long, thin metal rods that extend toward the foreground. In the background, intricate networks of pulleys, chains, and structural elements of the mill are visible. Running vertically along the left edge of the left image is the text "SAN FRANCISCO." and "ILLUSTRATED BY EDW. J. MUYBRIDGE." The same two lines of vertical text appear on the right edge of the right image. At the bottom center of the yellow mount, the words "PACIFIC ROLLING MILLS". Below the photograph, a gray-scale calibration strip with labeled shaded blocks is visible.