From Squash to Lava...

 

It was in one of Birmingham’s department stores, sometime in the late 60s or early 70s, that I got my first look at a lava lamp. We were in the furnishings department where several of the lamps were on display, and switched on. I’d never seen anything like them before, and was immediately intrigued at the writhing blobs of coloured 'lava' inside them. Quite apart from the unusual nature of the lamps, I was struck by their shape. I’d seen something like it before...

In the mid 60s, I’d noticed bottles of ‘Tree Top’ orange squash on sale in our local supermarket, and seen the brand advertised on television. ‘Tree Top’ was sold in a distinctively-shaped glass bottle, wide at the bottom, tapering to a narrower top with a deep plastic cap. These unusual lamps looked exactly like those old squash bottles, right down to the shape of the cap, and I remarked to myself on the similarity. For some reason, the shape of those squash bottles had appealed to me, and I now found myself similarly drawn to these strange psychedelic lamps as much for their shape as for their shape-shifting contents. The resemblance wasn’t coincidental – it happened that Edward Craven Walker, inventor of the lava lamp, had tried out his idea using various empty bottles, in the process of which he settled on the ‘Tree Top’ bottle as being the ideal container for his novel idea. The squash bottle formed the basis of what later became known as the ‘Astro Baby’ lamp, with a larger version employed as the more popular ‘Astro’. It was these that I’d seen on display in that department store – but they weren’t around for very long.

Lava lamps belonged to a passing interior décor fad that might be characterised as ‘psychedelic kitsch’, covering everything from Ercol armchairs to the paintings of Vladimir Tretchikoff, and spanning a period from the mid-60s to the early 70s. The lamps themselves had gone on sale back in 1963, and were famously featured in the TV series The Prisoner, where they appeared in various niches within the dwellings of Number Six and Number Two, and were also employed as part of the ‘Rover’ birthing sequence that spawned huge malevolent balloons from the bottom of the sea. Craven Walker had been inspired by a novel egg-timer he’d spotted in a Dorset pub, where water and wax had been combined in a heated bottle, and after various experiments, managed to turn it into a feasible table lamp, setting up the Crestworth company with his wife to bring it to market. Original Crestworth lamps came in a variety of sizes: the popular Astro lamp was joined by the scaled-down, ‘Tree Top’ bottle-sized Astro Baby, and a cylindrical version. The lamp bases and caps were originally a shiny copper colour, before changing to silver.

I never actually saw a lava lamp in anyone’s home during the 60s or 70s. My parents were far too conventional to give one house room, and even my cool relatives with their Jensen Interceptor and groovy 1970s furnishings didn't have one. By the mid 70s, lava lamps were already beginning to fall out of favour as interior décor trends began to embrace ‘country cottage’ traditional styles where Laura Ashley and William Morris held sway. The last time I saw a lava lamp in action during the 1970s was in the sitcom George and Mildred (1976-79). The Ropers’ living room had been decorated in deliberately bad taste, including a small lava lamp which would be turned on now and again to annoy Mildred’s brother-in-law (Reginald Marsh). Thereafter, I saw no more of them, and assumed, wrongly, that they’d vanished from the scene.

In fact, the company never stopped making the lamps, although they scaled back operations during the 1980s as demand tailed off. I didn’t see them again until the mid 1990s, when I spotted one on sale in a shop in Walsall. It was in what I took to be the ‘traditional’ colour scheme of red lava in blue liquid, and was turned on, doing its ‘thing’. By this time, the company had been taken over and renamed ‘Mathmos’ (after a lake of lava in the film Barbarella), and the lamps were suddenly popular all over again, coinciding with a resurgence of interest in mid-century retro interiors. Chris Evans had them dotted around his studio set in TFI Friday, and their psychedelic appearance sat well with the Acid House generation, as well as being popular with older hipsters keen to revisit their youth.

My original orange lava lamp, doing its thing back in the late 1990s

I got my first example at Christmas 1997, orange lava in a yellow medium. I was surprised at first to discover that the famous bubbling lava effect took over an hour to get going. After being switched on for maybe half an hour, the wax in the lamp base began to grow into extraordinary stalagmites and spires. Was this how they were supposed to work? Another half hour or more saw the curious structures begin to collapse and melt, eventually coalescing as a large, writhing blob at the bottom of the bottle. As convection develops in the liquid medium, the wax slowly begins to rise up, breaking off in bubbles which ascend to the top of the bottle before sinking back and dissolving back into the blob at the bottom. After three or four hours, the bubbles get smaller and smaller, as the convection process speeds up (the instructions advised users not to leave their lamps switched on much beyond this stage). If left on long enough, the wax would settle back into a blob at the bottom of the bottle as the temperature of the liquid medium evened out, reducing the effect of convection. Something I didn’t realise until researching this article is that there is a small metal coil embedded in the wax at the base, in order to break the surface tension when the wax softens, thus allowing bubbles to form and break away.

Surreal shapes appear during the 'start up' phase of any lava lamp:
this 'Astro Baby' created a scarily convincing nuclear explosion effect.

That lava lamp I got in 1997 is almost as old now as the originals were when I first acquired it, and it still works. The coloured water can occasionally fade over time, but the yellow medium in my example still looks more or less the same as it did nearly thirty years ago. As the lamps age, there is a tendency for blobs of ‘lava’ to get stuck at the top of the bottle, and if the bottle is agitated while the lamp is working, it can cause the clear liquid to become cloudy. What does one do with a lava lamp bottle when it reaches the end of its life? Don’t ask me – the four examples I own are all still doing their thing after more than a quarter of a century… I just know that you should definitely not pour the contents down the sink...

According to the Mathmos website, the average life span of a lamp is in the order of 2000 hours. I’ve used my original Astro sparingly over the years, and until recently, hadn’t switched it on for a very long time. It took at least an hour to get started, but once it reached the right temperature, it performed exactly as it always had. Assuming one leaves the lamp turned on for around four hours on a typical evening (they’re seen to best effect under low lighting), that 2000 hours equates to some 500 days’ use – around a year and a half if the lamp is used every day.

When lava lamps became popular again in the 1990s, it was soon possible to buy examples in a wide range of colours, and a few variants including one that included glitter flakes within the medium. The patent had lapsed by this time, allowing other manufacturers to get in on the act, and a lot of cheap versions soon appeared in the shops, retailing at less than half the price of the Mathmos originals. Of course, they were nowhere near as good to look at, and luckily the sales of these knock-offs doesn’t seem to have affected Mathmos, who continue to thrive to this day.

Edward Craven Walker died twenty five years ago, but his invention continues to delight anyone with an appreciation of mid century aesthetics. In an age when so many manufacturers get their products made on the cheap in the far East, it’s nice to be able to report that Mathmos lamps are still manufactured entirely in Britain. One might even call them the last gasp of so-called ‘cool Britannia.’ 

Now if only someone would reinvent Tree Top squash…