| Number | Name | Date | Kind |
|---|---|---|---|
| 898833 | Chapman | Sep 1908 | |
| 959843 | Cox et al. | May 1910 | |
| 1522636 | Landine | Jan 1925 | |
| 1987695 | McDonald | Jan 1935 | |
| 2848783 | Keller, Jr. et al. | Aug 1958 | |
| 4193594 | Schwauss | Mar 1980 |
| Entry |
|---|
| Psychological and Physiological Apparatus and Supplies, C. H. Stoelting Co. 1930, pp. 143 & 144, #31213 & #31223. |