Comparison of Full-Keyboard, Single-Shift, and Double-Shift Typerwriters in 1911

Description
English: Fig. 1: Machines with one character per key. Fig. 2: Machines with two characters per key. Fig. 3: Machines with three characters per key.
Date
Source Larousse mensuel illustré, 1911 (https://archive.org/stream/laroussemensueli02auguoft#page/163/mode/1up)
Author Anonymous engraver