This primary source comes from the Records of the Patent and Trademark Office.
National Archives Identifier:
6104271Full Citation: Patent Drawing for H. H. Waddington's Lawn Tennis Ball; 2/26/1889; 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://docsteach.org/documents/document/patent-drawing-for-h-h-waddingtons-lawn-tennis-ball, April 25, 2024]