The Blue John Caverns feature the largest veins of heavily banded fluorspar (calcium fluoride) known anywhere in the world; the only competitors are another mine in Castleton, Derbyshire, and a mine in China which has a similarly colored variety of the mineral. First discovered by the Romans over two millennia ago, the cave was mined for this material – intact vases made from Blue John fluorspar were found in the ruins of Pompeii. While the cave formations are naturally occurring, there are numerous shafts running in various directions from the caves, where miners have for centuries been systematically harvesting the Blue John fluorspar. It is rumored that Lord Mulgrave once gave the miners a feast in a large chamber of the cavern, which has become a part of the folklore surrounding it.
Perhaps even more interesting, it is the inspiration for one of Sir Arthur Conan Doyle’s short stories, “The Terror of Blue John Gap”. An almost-Lovecraftian attempt at cosmic horror, the story hints at the discovery of a vast subterranean void in which at least one terrible creature resides. A doctor, staying in the area for a rest cure for tuberculosis, becomes enmeshed in a series of mysteries that lead him to a final confrontation with the beast. While not up to the high bar set by Lovecraft shortly after its publication, the story – now available for free in the public domain – is still quite enjoyable.
As long as there has been photography, people have been photographing caves and caverns. Blue John Cavern is no exception – in fact, it was the site of the historic first use of magnesium for photographic lighting, on 27th January, 1865. Magnesium provided sufficient light to brighten a large cavern to the point that it could be recorded on the photographic plates of the day – which required significant light. These days, of course, that level of lighting is required, and by the time these VistaScreen views were produced in the 1950s, the cavern had been open for tours for decades, and was well-lit by electric lights, allowing photographs such as these.
While these VistaScreen views display the typical qualities one would expect of the amateurish Anglocentric upstart – dodgy compositions, not-so-black-blacks, high contrast, et cetera – they are far better than the images from earlier series such as that from ZSL London Zoo. And being real photographic prints, as opposed to the inferior lithographic views the company would make once acquired by Weetabix, they look quite good through a higher-quality viewer (I use a Raumbild viewer for VistaScreen). They are certainly more interesting as stereo images than black-and-white photographs of caverns tend to be – this is really an arena in which depth makes the image viable. Before examining the view through free-viewing, through a scope, or through the anaglyphs, look at any given single frame – they’re not compelling as photos go. So kudos to VistaScreen for producing this 3D set, as it’s unlikely that a major manufacturer (or even another small one without such a British focus) would take the time to document this location.