| Year | 1942 |
| Date | 10-Dec |
| Volume | 87 |
| Issue | 2,170 |
| Page | 573 |
| Category | General |
| Part | |
| Title | Suggestions for Small Engine Indicators |
| Author | D.A.Wrangham |
| Notes | Arising from recent letters, notes stress the need for clear understanding of scientific requirements. Prof. Perry's disc type of optical indicator, pressure component |