A pub, an egg timer, and an invention someone else already owned

Edward Craven Walker was a British accountant who’d spent World War II flying photo reconnaissance missions over Germany, and by the late 1940s he’d settled into running a travel business in London. Walker found his defining idea at a pub in Hampshire, where a regular named Donald Dunnett had rigged up a homemade egg timer from a cocktail shaker filled with two liquids that separated and bubbled as an egg boiled. Dunnett had actually patented that contraption, according to MIT’s Lemelson invention archive, which means Walker’s real contribution was the years he spent turning a kitchen timer into something people would want in their living room.

From cocktail shaker to a “revolting” orange squash bottle

Walker swapped the stovetop cocktail shaker for a light bulb as the heat source and settled on a formula combining wax, oil and more than a dozen other ingredients, including carbon tetrachloride, used to weight the wax. The bottle he eventually chose had started out holding Tree Top orange squash, a soft drink current Mathmos managing director Cressida Granger has since described as “a revolting drink we had in England growing up.”

The formula nobody’s ever fully published

Walker began selling his finished design under the name Astro Lamp in 1963, launching through London retailers Selfridges and Fortnum & Mason, and patented the design in England the following year. Two years later, American businessmen bought the U.S. manufacturing rights and built the Lava Lite brand around it.

From Selfridges to seven million lamps

The formula worked well enough that sales exceeded seven million units worldwide within its first years on the market. Demand cooled through the 1980s before a 1990s nostalgia wave pushed annual sales back over 800,000. The company, renamed Mathmos, marked the lamp’s 60th anniversary in 2023 with a run of limited-edition versions.

Walker stayed on as a consultant at his own company until his death in 2000, still tinkering with the formula he’d first spotted bubbling in a pan next to somebody’s dinner. Every genuinely new gadget from the era it was born in has long since been replaced by something faster; the lamp survived by never trying to be fast in the first place.