| ASTRA
1922 |
 |
| "In
Germany, an interesting case is the Astra produced by Astrawerke
in 1922. It was based on the Dalton machine but had [00, 000] multi-zero
keys." James Redin - A Brief History of Mechanical
Calculators - Part II |
| Photo Source:
Tullio
Parravicini - Calcolatrici &
Strumenti di Calcolo Meccanico. |