The First Fax Machine (Facsimile) — Alexander Bain’s 1843 Invention

Can you imagine transmitting a document electrically—more than three decades before the telephone was patented?

In 1843, Scottish inventor and clockmaker Alexander Bain patented his Electric Printing Telegraph, widely regarded as the conceptual ancestor of the fax machine.

How did it work?

A metal stylus, attached to a clock-controlled pendulum, swept across an electrically prepared image on a conductive surface.

Conductive area: Current flowed — ON

Non-conductive area: No current flowed — OFF

After every sweep, the original moved forward slightly, allowing the stylus to scan the next line. These electrical pulses travelled through a telegraph wire to a synchronized receiving mechanism.

At the receiver, another pendulum-driven stylus moved over chemically treated paper. Wherever current arrived, an electrochemical reaction produced a visible mark.

Thousands of such marks gradually reconstructed the original pattern, line by line.

Conductive image → Mechanical scanning → Electrical pulses → Telegraph wire → Chemical reproduction

The greatest engineering challenge was synchronization. Both pendulums had to sweep corresponding positions simultaneously; even a small timing error could skew or distort the reproduced image.

Bain’s apparatus could not transmit a normal grayscale photograph. It mainly reproduced conductive patterns, text and simple drawings. Nevertheless, it introduced the revolutionary principle of converting a two-dimensional image into a time-sequenced electrical signal—the foundation of later fax, scanning and television technologies.

Disclaimer: This post is based entirely on publicly available historical and technical sources and represents my limited technical interpretation. Bain’s experimental designs evolved over time, and terminology varies among historical accounts. Corrections and additional technical insights are most welcome.