| Year | 1940 |
| Date | 25-Jul |
| Volume | 83 |
| Issue | 2,046 |
| Page | 69 |
| Category | Horology |
| Part | |
| Title | Compensation with "Invar" |
| Author | G.G. |
| Notes | Relative expansion, computing the length proportion to compensate, approximating position of centre of oscillation, relative weights of bob and rod |