What does argand mean?
An argand is an oil lamp featuring a circular wick with a central air channel, enclosed by a glass chimney, invented around 1780 by the Swiss-born chemist Aimé Argand. By feeding oxygen to both the inner and outer surfaces of the flame, it produced a light far brighter and steadier than tallow candles or earlier oil lamps, making it a fixture of homes, libraries, and lighthouses throughout the nineteenth century until gas and electric lighting displaced it. In mathematics, the related term 'Argand diagram' denotes the standard two-dimensional plane used to visualize complex numbers, with real values plotted horizontally and imaginary values vertically — a representation popularized by the amateur mathematician Jean-Robert Argand. Today the lamp sense survives mainly in historical writing, while the diagram remains a staple of algebra and engineering education.
nounAn argand is an oil lamp with a tubular wick that admits air through its center and a glass chimney, producing a much brighter flame than earlier lamps. The term also refers to the Argand diagram, the graphical representation of complex numbers on a plane.
- An oil lamp with a circular hollow wick and glass chimney, invented by Aimé Argand in the late 18th century, giving a brighter, steadier light than candles.
- (In mathematics) the Argand diagram: a plane in which complex numbers are represented as points, with the horizontal axis for real parts and the vertical axis for imaginary parts.
"The drawing room was lit by a pair of brass argands whose steady white flames outshone any candle."
"Before gas lighting arrived, the argand was the brightest lamp most households could own."
"Students plot the complex number 3 + 4i as a point on the Argand diagram."
Used when referring to multiple lamps, as in period descriptions of interiors.
"Six argands illuminated the long dining table at the governor's residence."
The argand lamp burned so much brighter than candles that it was said to equal 'a dozen wax lights' — and it was invented by a Swiss chemist who never patented it properly, letting others profit from his glow.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of argand
The word derives from the surname of François-Pierre-Ami Argand (1750–1803), a Swiss chemist and inventor who developed his improved oil lamp in the late eighteenth century; the device took his name as an eponym. Separately, the 'Argand diagram' honors Jean-Robert Argand (1768–1822), a Geneva-born bookseller and amateur mathematician who published the plane representation of complex numbers in 1806. The two Argands were unrelated; the shared surname gave rise to two distinct technical terms in English.
How argand is actually used
The lamp sense is largely historical, encountered in discussions of 18th- and 19th-century domestic life and lighting technology. The mathematical sense is always used attributively ('Argand diagram', 'Argand plane') rather than as a standalone noun.