1. This rule appears to have been given away by Time Life. It came
in a plastic pouch and with documentation both of which mention Time Life.
2. A copy of the instructions can be found here.
C: C,D
| Slide rules HOME page | COLLECTION | CIRCULAR RULES |
| Make | Concise, Japan |
| Model | No 28N |
| Notes 1. This rule appears to have been given away by Time Life. It came
in a plastic pouch and with documentation both of which mention Time Life. |
|
| Front view |
Detail - front view |
| Detail - back view |
|
| Manufacturing date | 1960+ |
| Length | Circular |
| Material | Plastic |
| Scales | D, C, CI, A, K |
| Gauge points | p: A,B: C: C,D |
| Cursor | Plastic |
| Hair lines | |
| Documentation | Complete |
| Condition | Very good, include plastic case |