Napier Vacuum Machine

The Napier vacuum machine is a Victorian coffee maker from Scotland, usually dated to 1840, that brews coffee in an open jar and then uses a vacuum to draw it, filtered, into a sealed globe. It’s also called the Napier coffee machine, Napier coffee pot or “Napierian” machine. It’s a cousin of the siphon, with the parts laid out differently. Here’s how it works, how it was used, and why nobody quite agrees which Napier invented it.

The short version

• Two vessels: an open jar where the coffee brews, and a sealed globe that receives it.
• A bent tube links them, with a strainer and filter cloth on the end that sits in the coffee.
• Heat drives the air out of the globe; cooling creates a vacuum that pulls the coffee across.
• Dated to 1840 and never patented, according to Ukers.
• The inventor is disputed: Robert Napier, the Clyde shipbuilder, or his son James Robert Napier.

How does a Napier vacuum machine work?

The 1893 Encyclopaedia Britannica describes the machine as a glass globe, an infusing jar of glass or porcelain, and a bent tube of block tin or German silver, fitted by a cork into the neck of the globe and reaching to the bottom of the jar, where it ends in a finely perforated disc. A spirit lamp heats the globe.

1. The coffee infuses in the jar with boiling water, and a little boiling water goes in the globe.
2. Steam from the globe drives the air out down the tube, and it bubbles up through the coffee.
3. When the bubbles stop, almost all the air has gone. The lamp is taken away.
4. The steam condenses and leaves a vacuum. The coffee rushes up the tube to fill it, filtered on the way by the grounds that have settled around the perforated disc.

William Ukers, in All About Coffee (1922), describes the same idea with a silver globe, a “brewer”, a syphon and a strainer, with a metal strainer covered with a filter cloth on the end of the syphon tube.

A descendant writing on Hackaday describes it a little differently, with water pushed from the sealed vessel into the grounds and then drawn back. The two period sources above both have the coffee brewing in the open jar first, so this page follows them.

How do you use a Napier machine?

These steps follow Ukers’s description, with detail from the 1893 Britannica:

1. Put about half a cupful of water in the globe and seat it over the flame.
2. Put the dry coffee in the jar and fill it with boiling water.
3. Fit the tube into the neck of the globe so the strainer end sits in the coffee.
4. Light the lamp. The coffee is agitated by the bubbling for a few minutes.
5. When it goes still, turn the flame down or take the lamp away.
6. The vacuum draws the clear coffee through the strainer into the globe.

Neither source gives a coffee-to-water ratio, so I’d treat a surviving machine like any vacuum brewer and adjust to taste.

General guidance only. Antique vacuum brewers use an open flame and hot glass or metal under pressure. Never leave one unattended, and have an old machine checked before using it.

Who invented the Napier coffee machine?

This is genuinely disputed, so here are both sides:

Claim	Who says so
Robert Napier (1791 to 1876), Scottish marine engineer of Robert Napier and Sons, Clyde shipbuilders	William Ukers, All About Coffee (1922)
James Robert Napier, his son, born in Glasgow in 1821	Wikipedia, and a family history on Hackaday by one of his descendants

Both agree on 1840 and that it was never patented. Ukers tells a story that the elderly Mr Napier, after a dispute at the Glasgow works where it was made, told the silversmith, “You may be a guid silversmith, but I am a better engineer.” Treat that as an anecdote rather than a record.

A short history of the Napier machine

• 1839: Ukers records an English patent to James Vardy and Moritz Platow for an urn using the vacuum process, with a glass upper vessel.
• 1840: the Napier machine is dated to this year, and never patented.
• 1842: Ukers says the first French patent on a glass vacuum coffee maker went to Madame Vassieux of Lyons.
• About 1870: Thomas Smith and Son (later Elkington and Co.) begin making the “Napierian” machine in Glasgow, according to Ukers.
• 1891: the Napier-List steam coffee machine, for hotels, ships and restaurants, is patented in England as an improvement on the Napier system.
• 1922: Ukers says the machine “has enjoyed great popularity in England” and was still being made by Elkington.

Napier machine vs other methods

• Siphon: the stacked vacuum pot most people know today.
• Cona: a British all-glass vacuum brewer with a glass rod filter.
• Belgian balance siphon: side by side like the Napier, with a counterweight that snuffs the flame.
• French press: simple immersion, with a mesh filter instead of a vacuum.
• Stovetop percolator: another 19th-century way to cycle water through coffee.

Explore every vacuum brewer in the vacuum chapter.