| Year | 1957 |
| Date | 21-Feb |
| Volume | 116 |
| Issue | 2,909 |
| Page | 265 |
| Category | Optical |
| Part | |
| Title | A 35 mm. transparency projector.. |
| Author | H.J.Turpin |
| Notes | Constructional details. Diagrammatic lens system, construction, general arrangement, slide holder details, making the case, various components |