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The Can Opener

Summer 2000 | Volume 16 |  Issue 1

DURING THE 1820S THE BRITISH EXPLORER WIL liam Parry led several Arctic expeditions across Baffin Bay and through miles of frozen waste toward the north magnetic pole. The explorers used a new technology to help them survive in the frigid north: canned food. Tin-coated, wrought-iron cans would allow them to carry palatable provisions almost indefinitely without spoilage. The trouble began when they actually wanted to eat the food. A can of roast veal came with these forbidding instructions: “Cut round on the top with a chisel and hammer.”

A British engineer and paper manufacturer named Bryan Donkin, building on the work of the French inventor Nicolas Appert, had developed a process for preserving food in metal cans in 1812. “It is the rare artifact that does not require also an infrastructure of auxiliary artifacts to be developed,” the author and engineer Henry Petroski observes in his book The Evolution of Useful Things . Donkin apparently figured that was someone else’s problem.

Ever since bayonets and gunfire, progress has been slow

Early cans were mighty fortresses of heavy-gauge wrought iron that often weighed more than the food they contained. Soldiers in the early nineteenth century attacked them with bayonets. As late as the American Civil War, hungry troops resorted to rifle fire to open them.

The first can openers weren’t a big improvement. Piercing the lid required a forceful blow with a sharp instrument. Then one had to saw laboriously around the rim to get at the contents of the can. It was messy and even dangerous. Consumers usually made do with their own tools or let shopkeepers open the cans for them.

The outlook brightened in the late 1850s, when manufacturers became able to produce thinner cans from steel. In 1858 Ezra Warner, of Waterbury, Connecticut, patented a breakthrough: an opener with a pointed blade that the user pressed, rather than stabbed, into the can. A metal guard kept the point from penetrating too far, to “perforate the tin without causing the liquid to fly out.” A second, curved blade could then be worked to gnaw along the rim and remove the lid. Warner’s patent claimed, with more optimism than prudence, that “a child may use it without difficulty, or risk.”

The first widely used domestic can opener, the late-nineteenth-century Bull’s Head, was named for the sculptural shape of the cast-iron handle end that held its blade. It typically had a short, pointed blade to pierce the lid and a longer blade to slice along the rim, much in the manner of Warner’s 1858 opener. The Bull’s Head was so popular that today it can often be found in antique shops and on eBay.

William Lyman, of West Meriden, Connecticut, had described a startlingly modern approach to can-opener technology in his 1870 patent: He introduced the cutting wheel. His design had serious drawbacks, however. You had to pierce the exact center of the lid with one end of the opener and use that as a pivot for the cutting wheel, and the device had to be adjusted to accommodate cans of different sizes.

The can opener entered the modern age in 1925, when the Star Can Opener Company of San Francisco improved on Lyman’s wheel blade by adding a second, serrated wheel, called a “feed wheel” or “turning gear,” to ride below the rim of the can. By squeezing the rim between the two wheels, the Star maintained a firm and steady grip on the can. Electric can openers, introduced in 1931, operated on the same basic principles, as they still do today.

The technology of opening beverage cans has followed a different course. Breweries and soda pop manufacturers used tin cans not for long-term preservation but as a cheap, disposable alternative to glass bottles. You usually didn’t want to remove the whole lid when the can held a drink. The familiar “church key” opener forced down a triangular flap of lid, leaving an aperture through which to sip, guzzle, or pour.

The development of extremely thin-walled aluminum cans in the late 1950s allowed for cans that could be opened without special tools. A ring attached to a scored flap on the top of the can provided easy access—and generated an astonishing amount of litter. For more than a decade discarded pull-tabs were as common as crabgrass, until beverage makers came up with tabs that remained attached to the can after opening- and such tabs became required by law.

Can opener design hasn’t changed much in the last 70 years, despite ample room for improvement. The common type of hand-operated opener usually allows the lid to fall into the can, leaving a sharp-edged metal disk to retrieve. A less common design circumvents this problem by placing the cutting wheel below the rim, which therefore comes off with the lid; this leaves a sharp edge on the can itself.

Old-style openers, with a single blade for piercing and cutting, haven’t completely disappeared. Campers to this day use the so-called “John Wayne,” a standard feature on Swiss Army and other pocketknives. Some electric openers feature a magnet that holds on to the lid, and many include accessories for opening bottles, jars, and plastic bags or, for some reason, for sharpening knives. They’re relatively inexpensive, starting at under $20, but they compete with coffeemakers and toaster ovens for counter space.

Perhaps the coming decades will at last bring, along with dramatic strides in information technology, genetic engineering, and subatomic physics, the perfect can opener. Or perhaps, as happened with beverage cans, the package will evolve to where the opener is no longer necessary.

We hope you enjoyed this essay.

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