Many other scientists tried to replicate his experiments. Sir William Crookes claimed success in 1909.[8] Otto Ruff claimed in 1917 to have produced diamonds up to 7 mm in diameter,[9] but later retracted his statement.[10] In 1926, Dr. J Willard Hershey of McPherson College replicated Moissan's and Ruff's experiments,[11][12] producing a synthetic diamond; that specimen is on display at the McPherson Museum in Kansas.[13] Despite the claims of Moissan, Ruff, and Hershey, other experimenters were unable to reproduce their synthesis.[14][15]