The beautifully designed Moka Pot, equally ubiquitous and divisive among coffee fans, was invented in 1933 by Luigi di Ponti. The machine was quickly put into production by a mustachioed metal machinist from Piedmont, Alfonso Bialetti, who transformed di Ponti's so-called "Moka Express", an aluminum, pressure-driven stove-top coffee brewer, into one of the most famous, familiar brewers in the world.
Though it's essentially a percolating device, Bialetti legend suggests that the machine was inspired by early clothes-washing machines which used a heat source to boil a pail of sudsy water and cause it to rise up out of a tube, which could be aimed at soiled laundry. Instead, of course, the Moka Express causes hot water to pass upwards, through coffee grounds, and rise up out of a tube—meaning brewed coffee does not have to pass through any additional coffee filters, as the grounds stay below the final extraction.
The charmingly octagonal Moka Pot, sometimes also called a caffettiera, a macchinetta or stovetop espresso maker, carries with it a strong, sludgy cup of historical significance in coffee. As a design piece, it's internationally renowned, rivaled perhaps only in comeliness by the Chemex. (Look for both in the Cooper-Hewitt, National Design Museum, and many others.) As an industrial innovation, it's noteworthy, too: the brewer's aluminum construction was revolutionary in coffee at that time, and the brewer's gradual rise in popularity dovetailed with a modernist shift towards aluminum's prominence in the kitchen. (Many contemporary models are, however, available made of stainless steel, and even available in smoother, sexier shapes, like the design named "Venus".)
Culturally, the Moka Pot marked a historical shift from espresso as an out-of-the-house-only beverage to one that could be approximated in the home, which coincided nicely with Italy's economic downturn of the 1930s. Bearing in mind that espresso made in commercial-grade machines is brewed with a much higher amount of pressure (9 bar) than the boiling water in a stovetop pot can provide (maybe 2 bar, if you're lucky), these brewers are able to produce an intense, concentrated brew that many home drinkers enjoy as a substitute for traditional espresso. This democratization of a style of coffee that was previously tied to a cafe or restaurant experience was one of the first home brewing revolutions.
To brew, water is placed in the lower chamber of the pot (starting with very hot water works best, to avoid "baking" your coffee grounds before extraction begins), and drip-sized ground coffee is placed evenly in the coffee chamber. The pot is then placed on a heat source, lid open, where water heated slowly over medium-high heat will eventually boil and rise through the coffee, extracting it, and sending it up the spout into the top chamber. Once it's finished extracting, one may close the lid and dispense their strong brew from their historic octagonal pitcher.
In 1953, the company commissioned a drawing that would become as iconic as the Moka Express itself: a drawing of Bialetti as a pointy-fingered, squat man with an impressive moustache. (The moustachioed little man adorns the side of Bialetti Moka pots to this day.)
While it's not for everyone—many argue poor extraction and metallic taste among the Moka's shortcomings—it's a method of brewing venerated by many, and worthy of respect in the continued canon of coffee invention and innovation. (After all, if a metalworker had never made a home espresso maker, a flying-ring sports toy manufacturer probably wouldn't have invented one either.)