Lava lamp Astro Lamp

Classic Projects: Astro Lamp, the story of the lava lamp

Image credit: Dreamstime

The story of the Astro Lamp, the lava lamp that sold in the millions thanks to Ringo Starr and Doctor Who. Its bright colours and weird movements, coupled with its massive popularity, turned the Astro lava lamp into an enduring symbol of the 1960s.

An early duotone advertisement for the ‘Astro’ lamp, declared it to be the perfect gift “for one’s relatives, one’s friends – and, dash it all, oneself”. Not only this, but it is a conversation piece styled to “fit any mood, any décor in the home and all discerning establishments”.

In any decade other than the 1960s, it would have been categorised an ‘executive toy’. Yet the Astro lamp, consisting of a bolus of wax heated by a light bulb, rising and falling in a tapered glass vessel of coloured liquid, was much more important than that. The ‘lava lamp’ as it later became known, with its Pop Art colours and obvious relationship with psychedelia, was to become a byword for the 1960s, selling by the millions. It became a major fad once a shop in Birkenhead announced Ringo Starr had bought one, and it received another sales boost after it appeared in several episodes of ‘Doctor Who’.

The attraction of the lamp was, of course, interaction of two liquids (‘master fluid’ and ‘moving base’) of suitably contrasting colours, as they were heated and illuminated from below by an incandescent light bulb (radiation). The constantly shifting alien-looking shapes were mesmerising and contemporary accounts relate the experience elicited feelings of ‘grooviness’, situated in a theoretical ‘far out’ region.

The principle at work is the ‘Rayleigh-Taylor instability’, related to the interface of two liquids. This is the same phenomenon that keeps oil and water separate and creates mushroom clouds after nuclear explosions. The wax cycles from bottom to top of the cylinder and back again (convection), becoming less dense as it warms and more dense as it cools. In the process, the wax bears an uncanny resemblance to a specific type of volcanic lava called pahoehoe, which is the origin of the name-change to ‘lava lamp’. In the base is a wire coil that acts as a surface tension breaker, allowing blobs of sunken wax to recombine before starting their journey back to the top.

The idea had its origins in British accountant Edward Craven-Walker’s visit to a pub in Dorset. The pub used a device employing two liquids of unequal density as a rudimentary egg timer. History does not relate quite why Craven-Walker then chose to spend 15 years developing this concept into a liquid-filled standard lamp. Suffice to say, he did, and by 1963 the invention was in place, with US patent 3,387,396 filed in 1965 (the same year the American rights were sold at a trade show in Germany) and issued in 1968. Craven-Walker kept hold of the rights for the rest of the world, restructuring his manufacturing business, while changing its name from Crestworth to Mathmos (which comes from the 1968 film ‘Barbarella’, where Mathmos is a lake of lava underneath the city of Sogo).

Under these two names, the company has made lava lamps of largely unchanged design for more than half a century. It was, of course, a hot property through the 1960s and 1970s, but the cooling of the trend saw its manufacture sink to a mere 1,000 units a year by 1989. However, with the new Mathmos banner, and a little help from an ‘Austin Powers’-inspired nostalgia for the 1960s, it was hot once more, selling close to one million units in 2000.

One final thought: it doesn’t cast much light, does it? This, says Stephen Horner, lighting expert and teacher of lighting design at the Pratt Institute, Brooklyn, New York, is because it is “more a ‘mood creator’. It harkens back to one of our most ancient forms of amusement: the flickering hearth. Yet the rocket-like design was perfectly pitched for the space age.”

Astro Lamp facts 

Date: 1948-1963
Designer: Edward Craven-Walker
Cost: Today, from £70

Invented in 1948, but took 15 years to appear on market

Inventor Edward Craven-Walker was a Second World War pilot and naturist (not, we gather, at the same time)

Exact formula for both master fluid and moving base are close secrets

Based on a liquid-motion egg timer invented by Donald Dunnet

Originally called ‘Astro’ lamps

The name ‘lava’ comes from the resemblance to molten pahoehoe

Early versions included carbon tetrachloride

The underlying fluid dynamics is a form of Rayleigh-Taylor instability

It takes 45-60 minutes for a lava lamp to get working

The patent cites the product as a ‘display device’

Original master fluid colours: rose, primrose, clear, yellow/green, blue/green

Original base fluid colours: ruby, topaz, amber, emerald

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