Crop of page 159 of the 1974 Pitt student yearbook, The Owl. This work was originally published from 1923 through 1977 without a copyright notice. Therefore, the work is in the public domain due to failure to comply with required formalities.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.