Hand lead line with tallow
Sonda de mano con plomo y sebo
- Date
- century V a.C. (descrita por Heródoto) · confidence low
- Place
- Nile Delta, Egypt
- Credited to
- Egyptian and Greek mariners
- Field
- Movement
⚠️ Disputed: the sources disagree.
What it is
A marked line with a lead weight, tallow in its base picking up sand or mud from the bottom. It gives depth and type of seabed and lets a ship approach the coast in fog or at night.
Egyptian reliefs show sounding poles from early periods; the lead line appears in Herodotus (II, 5) and in the Acts of the Apostles. Its exact origin is unknowable.
What it led to
- safe coastal navigation and harbour entry
- charts with soundings and bottom type
- 19th-century deep-sea sounding