The Jacquard Loom

jacquard2The Jacquard Loom is a mechanical loom that has holes punched in pasteboard, each row of which corresponds to one row of the design. Multiple rows of holes are punched on each card and the many cards that compose the design of the textile are strung together in order.

Jacquard_Joseph_Marie_woven_silk

This portrait of Jacquard was woven in silk on a Jacquard loom and required 24,000 punched cards to create (1839). It was only produced to order. Charles Babbage owned one of these portraits; it inspired him in using perforated cards in his analytical engine. It is in the collection of the Science Museum in London, England.

In order to discuss the Jacquard loom, some basic knowledge of weaving is necessary. In order to make a strip of cloth, parallel threads (the “warp”) are stretched across a rectangular frame. To make a plain piece of cloth, every other warp thread is raised slightly. A thread (the “weft thread”) is then passed (at a right angle to the warp) through the space (the “shed”) between the lower and the upper warp threads. The raised warp threads are then lowered and the previously lower warp threads are raised, and the weft thread is then passed through the shed in the opposite direction. The process can then be repeated indefinitely.

However, by raising different warp threads during weaving, it is possible to make fabrics of different textures or to vary the texture, or even the color, of the cloth in order to create patterns or designs. When elaborate patterns or designs were to be woven manually, selecting the warp threads that were to be raised became a slow, complicated procedure that was subject to error. Jacquard’s loom was intended to automate this process.

Jacquard was not the first man to try to automate the process of weaving. In 1725 Basile Bouchon invented an attachment for draw looms which used a broad strip of punched paper to select the warp threads that would be raised during weaving. Specifically, Bouchon’s innovation involved a row of hooks. The curved portion of each hook snagged a string that could raise one of the warp threads, whereas the straight portion of each hook pressed against the punched paper, which was draped around a perforated cylinder. Whenever the hook pressed against the solid paper, pushing the cylinder forward would raise the corresponding warp thread; whereas whenever the hook met a hole in the paper, pushing the cylinder forward would allow the hook to slip inside the cylinder and the corresponding warp thread would not be raised. Bouchon’s loom was unsuccessful because it could handle only a modest number of warp threads.

By 1737, a master silk weaver of Lyon, Jean Falcon, had increased the number of warp threads that the loom could handle automatically. He developed an attachment for looms in which Bouchon’s paper strip was replaced by a chain of punched cards, which could deflect multiple rows of hooks simultaneously. Like Bouchon, Falcon used a “cylinder” (actually, a four-sided perforated tube) to hold each card in place while it was pressed against the rows of hooks. His loom was modestly successful; about 40 such looms had been sold by 1762.

In 1741, Jacques de Vaucanson, a French inventor who designed and built automated mechanical toys, was appointed inspector of silk factories. Between 1747 and 1750, he tried to automate Bouchon’s mechanism. In Vaucanson’s mechanism, the hooks that were to lift the warp threads were selected by long pins or “needles”, which were pressed against a sheet of punched paper that was draped around a perforated cylinder. Specifically, each hook passed at a right angle through an eyelet of a needle. When the cylinder was pressed against the array of needles, some of the needles, pressing against solid paper, would move forward, which in turn would tilt the corresponding hooks. The hooks that were tilted would not be raised, so the warp threads that were snagged by those hooks would remain in place; however, the hooks that were not tilted, would be raised, and the warp threads that were snagged by those hooks would also be raised. By placing his mechanism above the loom, Vaucanson eliminated the complicated system of weights and cords (tail cords, simple, pulley box, etc.) that had been used to select which warp threads were to be raised during weaving. Vaucanson also added a ratchet mechanism to advance the punched paper each time that the cylinder was pushed against the row of hooks. However, Vaucanson’s loom was not successful. Its mechanism was not successful probably because, like Bouchon’s mechanism, it could not control enough warp threads — and hence it could not weave patterns that were sufficiently elaborate — to justify the cost of the mechanism.

In order to stimulate the French textile industry, which was competing with Britain’s industrialized textile industry, Napoleon Bonaparte placed large orders for Lyon’s silk, starting in 1802. In 1804, at the urging of Lyon silk merchant Gabriel Detilleu, Jacquard studied Vaucanson’s loom, which was stored at the Conservatoire des Arts et Métiers in Paris. By 1805 Jacquard had eliminated the paper strip from Vaucanson’s mechanism and returned to using Falcon’s chain of punched cards.

The potential of Jacquard’s loom was immediately recognized. On April 12, 1805, emperor Napoleon and empress Josephine visited Lyon, and during their tour, they viewed Jacquard’s new loom. On April 15, 1805, the emperor granted the patent for Jacquard’s loom to the city of Lyon. In return, Jacquard received a lifelong pension of 3,000 francs; furthermore, he received a royalty of 50 francs for each loom that was bought and used during the period from 1805 through 1811.

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