Historians and researchers have finally solved a long-standing mystery behind one of Victorian England’s iconic architectural wonders. The answer? Simple, standardized nuts and bolts. That may not sound too exciting today, but in 1851, the invention allowed engineers to build the Crystal Palace at previously unimaginable speeds.
While the Great Exhibition of 1851 showcased Britain’s most advanced and acclaimed industrial capabilities across a number of exhibits, the five-month-long event’s crown jewel undoubtedly came from architect Joseph Paxton. At over 1,827-feet-long, the Crystal Palace was the world’s largest building at the time, and featured a huge glass roof supported by 3,300 cast iron columns. For nearly 175 years, however, a mystery has left historians puzzled—how was it possible for Paxton’s workers to complete construction in only 190 days?
A study published in The International Journal for the History of Engineering & Technology now has solved the mystery. According to John Gardner, a professor of English literature at Anglia Ruskin University (ARU), the Crystal Palace relied on a revolutionary screw thread designed by a man named Joseph Whitmore.
Before Whitworth’s standardized concept, every screw and bolt was unique to one another without standardized measurements. This meant that lost screws or broken bolts could easily grind construction projects down to a standstill, at least until someone fashioned new replacements. Given its immense size and complexity, the Crystal Palace alone needed 30,000 nuts and bolts—and yet requiring so many pieces somehow didn’t hinder the building’s construction.
“The forms of screw threads used in Crystal Palace buildings have not been recorded in any of the surviving drawings,” Gardner and his co-author Ken Kiss wrote in their paper. “Furthermore, none of the rare existing bolt threads have been measured, recorded and published, until [now].”
The reason behind the original bolts’ rarity is that, after its deconstruction in Hyde Park and subsequent rebuilding in south London in 1854, the Crystal Palace burned down in 1936. But Kiss, curator for the Crystal Palace Museum, excavated one of the last known bolts from a column at the building’s original site, as well as a nearby water tower built at the time to power the palace fountains. Kiss then provided these archeological artifacts to Gardner for analysis.
Gardner found the Crystal Palace column bolt matched exactly to Whitworth’s measurements, years before it became known as the British Standard Whitworth (BSW), the world’s first national specification of its kind. After soaking the water tower’s nut and bolt in oil, then using a combination of heat, force, and hammering, he also uncovered measurable screw threads that also matched the BSW specifications. To further prove his theory, Gardner manufactured completely new bolts to BSW threading, which fit perfectly with the original nut.
According to the study co-authors, adopting Whitworth’s new, standardized option allowed builders to complete the monumental endeavor in a comparatively short period of time. The results were ultimately seen by around six million visitors to the Great Exhibition between May and October of 1851. But as to why such a detail remained overlooked for decades, Gardner pointed to the pace of revolutionary technology changes at the time.
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“During the Victorian era there was incredible innovation from workshops right across Britain that was helping to change the world,” Gardner said in an accompanying statement. “In fact, progress was happening at such a rate that certain breakthroughs were perhaps never properly realized at the time, as was the case here with the Crystal Palace.”
Like the Crystal Palace itself, the exact BSW specifications aren’t often used today—but its legacy influenced a number of modern variants that don’t stray too far from the original measurements. Similarly, the Crystal Palace, while now long gone, helped inspire modern architecture for decades to come.
