| RGO Archives/RGO 9 contains: |
| <-- See earlier |
| 101 |
Correspondence on the mirror transit instrument |
| 102 |
Correspondence on the meridian circle |
| 103 |
Correspondence on the Yapp Telescope |
| 104 |
Correspondence on the Schmidt Telescope |
| 105 |
Correspondence on the reversible transit circle |
| 106 |
Correspondence on cosmic ray instruments |
| 107 |
Correspondence on the spectroheliograph reflector |
| 108 |
Correspondence on the stellar photometer |
| 109 |
Correspondence on the astrographic telescope. |
| 110 |
Correspondence on photographic zenith tubes |
| 111 |
Correspondence on the photographic zenith tube |
| See later --> |