Loom with punched tape

The Jacquard loom, perfected in 1804, used punched cards to control complex weaving patterns—the same principle that would govern computer programming for 150 years. Joseph Marie Jacquard did not invent punched-card control; he refined techniques developed by Basile Bouchon (1725) and Jacques de Vaucanson (1745) into a practical system that transformed textile manufacturing.

The mechanism used cards with holes punched in specific positions. Each card controlled one row of the weave; a chain of cards could produce patterns of arbitrary complexity. Where a hole existed, a hook passed through and raised a thread; where card remained, the hook was blocked. By changing the card chain, weavers could change patterns without rebuilding the loom.

Vaucanson had used perforated paper tape; Jacquard switched to sturdy cards that could be reused and reconfigured. This improvement made the system practical for production use. Silk merchants in Lyon adopted Jacquard looms rapidly, despite violent resistance from workers who feared displacement.

The adjacent possible extended backward to player pianos and forward to Charles Babbage. Automated musical instruments had used pinned cylinders for centuries; the switch to punched media was conceptually small but practically important. Babbage explicitly acknowledged Jacquard's influence on his Analytical Engine, the theoretical ancestor of modern computers. Herman Hollerith used punched cards for the 1890 U.S. Census; IBM built a corporate empire on the same technology.

The principle—storing programs as patterns of holes in a physical medium—dominated computing until magnetic storage superseded it. Early programmers learned to read punched cards by eye; dropping a card deck could ruin hours of work. The FORTRAN and COBOL programming languages were designed around the 80-column card format.

A weaver's need to specify complex patterns produced an information storage and retrieval system that would structure computation for generations.