Lewis (stone block lifting device)
Lewis (garra de elevación de bloques de piedra)
- Date
- c. century I a.C. · confidence low
- Place
- Rome, Lazio, Italy
- Credited to
- Roman builders
- Field
- Tools
⚠️ Disputed: the sources disagree.
What it is
Three iron pieces (two side wedges and a central pin) fitted into a dovetail-shaped hole cut in the top face of the block, gripping it without external ropes or tongs so it can be raised by a crane. The holes survive in Roman ashlar blocks.
Its modern name comes from an 18th-century English builder; the dovetail holes in Roman and late Greek blocks are interpreted as lewis holes, although classical Greece also used bosses and tongs.
What it led to
- setting heavy ashlar with pulley cranes
- large-block Roman masonry in temples and amphitheatres
- the masons' lifting claw until the 19th century