| Year | 1915 |
| Date | 02-Dec |
| Volume | 33 |
| Issue | 762 |
| Page | 459 |
| Category | General |
| Part | |
| Title | Elementary Principles of the Bi-Pendulum Harmonograph |
| Author | Bettesworth Page |
| Notes | The Connection between the Slow Vibrations of the Pendulum and the more Rapid Vibrations Producing Sound, with a description of the Phonoscope. A simple arc indicator, some figures produced by various ratios, the rapid regular vibrations |