Fax machine

The fax machine's origins predate the telephone by over three decades, a reminder that the adjacent possible often opens earlier than practical adoption. Scottish inventor Alexander Bain patented the concept of an 'electric printing telegraph' on May 27, 1843, using synchronized pendulums to scan and reproduce images line by line. The telegraph was barely a decade old, yet Bain had already conceived of transmitting exact copies—'fac-simile' in Latin—across wires.

Bain's experimental device, developed between 1843 and 1846, used a metal stylus to scan raised metal letters, transmitting the contact patterns electrically. The receiving end reproduced the image using electrochemical paper that darkened when current passed through. The fundamental principle—scanning images into sequential signals that could be transmitted and reconstructed—established the template that all subsequent fax technology would follow.

The commercial breakthrough came with Italian physicist Giovanni Caselli's pantelegraph, which operated between Paris and Lyon from 1865. Unlike Bain's experimental device, Caselli's system used a regulating clock to synchronize sender and receiver—solving the critical problem of keeping two distant machines in lockstep. The pantelegraph sent thousands of faxes yearly, demonstrating commercial viability two decades before the telephone existed.

The path dependence of early facsimile technology would persist for over a century. Each generation improved on the same fundamental approach: scanning images line by line, converting to electrical signals, transmitting over wire networks, and reconstructing at the destination. Wirephoto services in the early 20th century adapted the technology for newspaper photograph transmission. The Xerox LDX system in 1964 integrated xerographic printing, producing dry copies instead of wet electrochemical paper.

The fax machine's remarkable longevity—remaining in widespread use into the 2020s, especially in healthcare, legal, and Japanese business contexts—illustrates how path dependence can sustain technologies long past their technical obsolescence. Once fax numbers are embedded in regulatory requirements, legal practices, and business processes, the network effects of compatibility outweigh the technical superiority of alternatives.