Merrill, Robert H., 1881-1955, “Ladder & metric grid on rug, shade Macatawa,” Digital Collections, accessed March 31, 2025, https://digitalcollections.library.gvsu.edu/document/50420.
Black and white photograph of two metric measuring grid squares next to a measuring stick on a rug. Part of a camera ladder rig system developed by Merrill for taking overhead photographs of archaeological excavations.