A 3D model of U.S. Pat. No. 267,812. Cutting edge 1882 page holder technology from the original Thingiverseâ€”the U.S. PTO.
"To all whom it may concern: Be it known that we, CELIA J. B. WHITEHEAD and EMORY J. WHITEHEAD, citizens of New Jersey, United States of America, residing at Bloomfield, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Book-Holders; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.