This primary source comes from the Records of the Patent and Trademark Office.
National Archives Identifier:
1593220Full Citation: Patent Drawing for A. K. Shaap's Mask for Base Ball Catchers; 10/23/1883; Utility Patent Drawings, 1837 - 1911; Records of the Patent and Trademark Office, Record Group 241; National Archives at College Park, College Park, MD. [Online Version, https://www.docsteach.org/documents/document/drawing-of-a-mask-for-base-ball-catchers, April 18, 2024]