
1847 / Book or monograph
A Code of Signals ... in the Merchant Service
Communication, telegraphy and codes · Navigation, seamanship and maritime practice
271 pages Open documentOpening preserved document…

Bibliographic identity checked against available scan and source evidence.
Digitizing archive catalogue
https://archive.org/details/youngseaofficers00leve_0
obscure/lever-sheet-anchor-1808.pdf
SHA-256: 9e55dfb4afff8ac2ba7f9d8b918835e7be8263c001f5a2e650b255b02877b293
Catalogue reviewed 19 September 2026. Original scans retained; catalogue labels do not endorse historical claims.