Subject
- Surveying[remove]8
- Aerial navigation1
- Airfields1
- Airspace (international law)1
- Boundaries1
- Central Persia Telegraph Line1
- Climatic data1
- Customs duty1
- Diaries1
- Expenses1
- First Anglo-Afghan War (1838-1842)1
- Frontiers1
- Geographical exploration1
- Military affairs1
- Military intelligence1
- Plans1
- Political intelligence1
- State visits1
- Steamships1
- Telegraph lines1